Merge tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH: "Here is the large TTY/Serial driver set of patches for 4.21-rc1. A number of small serial driver changes along with some good tty core fixes for long-reported issues with locking. There is also a new console font added to the tree, for high-res screens, so that should be helpful for many. The last patch in the series is a revert of an older one in the tree, it came late but it resolves a reported issue that linux-next was having for some people. Full details are in the shortlog, and all of these, with the exception of the revert, have been in linux-next for a while with no reported issues" * tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits) Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250" serial: sccnxp: Allow to use non-standard baud rates serial: sccnxp: Adds a delay between sequential read/write cycles tty: serial: qcom_geni_serial: Fix UART hang tty: serial: qcom_geni_serial: Fix wrap around of TX buffer serial: max310x: Fix tx_empty() callback dt-bindings: serial: sh-sci: Document r8a774c0 bindings dt-bindings: serial: sh-sci: Document r8a774a1 bindings Fonts: New Terminus large console font dt-bindings: serial: lpuart: add imx8qxp compatible string serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly serial: uartps: Fix error path when alloc failed serial: uartps: Check if the device is a console serial: uartps: Add the device_init_wakeup tty: serial: samsung: Increase maximum baudrate tty: serial: samsung: Properly set flags in autoCTS mode tty: Use of_node_name_{eq,prefix} for node name comparisons tty/serial: do not free trasnmit buffer page under port lock serial: 8250: Rate limit serial port rx interrupts during input overruns dt-bindings: serial: 8250: Add rate limit for serial port input overruns ...
author: Linus Torvalds <torvalds@linux-foundation.org> 2018-12-28 20:33:54 -0800
committer: Linus Torvalds <torvalds@linux-foundation.org> 2018-12-28 20:33:54 -0800
commit: 117eda8f71ff545cfdec8fe8073adbd173a1ceff (patch)
tree: 7a6fe1729d34581c563b5f7a883f049ee272f1e3 /drivers/tty
parent: c0ea81b4d37837409d0dfd2036098a7babb312ed (diff)
parent: 598134ffcab5bfb1d342458732394487063e1b9e (diff)
36 files changed, 803 insertions, 301 deletions
diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index 77baf895108f..c66412566efc 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -353,7 +353,7 @@ void __init hvc_opal_init_early(void)
 		if (!opal)
 			return;
 		for_each_child_of_node(opal, np) {
-			if (!strcmp(np->name, "serial")) {
+			if (of_node_name_eq(np, "serial")) {
 				stdout_node = np;
 				break;
 			}
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
index 59eaa620bf13..6de6d4a1a221 100644
--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -371,20 +371,11 @@ device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
 void __init hvc_vio_init_early(void)
 {
 	const __be32 *termno;
-	const char *name;
 	const struct hv_ops *ops;
 
 	/* find the boot console from /chosen/stdout */
-	if (!of_stdout)
-		return;
-	name = of_get_property(of_stdout, "name", NULL);
-	if (!name) {
-		printk(KERN_WARNING "stdout node missing 'name' property!\n");
-		return;
-	}
-
 	/* Check if it's a virtual terminal */
-	if (strncmp(name, "vty", 3) != 0)
+	if (!of_node_name_prefix(of_stdout, "vty"))
 		return;
 	termno = of_get_property(of_stdout, "reg", NULL);
 	if (termno == NULL)
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index dabb391909aa..99460af61b77 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -612,7 +612,7 @@ static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
 		}
 			
 		/* no data */
-		if (file->f_flags & O_NONBLOCK) {
+		if (tty_io_nonblock(tty, file)) {
 			ret = -EAGAIN;
 			break;
 		}
@@ -679,7 +679,7 @@ static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
 		if (tbuf)
 			break;
 
-		if (file->f_flags & O_NONBLOCK) {
+		if (tty_io_nonblock(tty, file)) {
 			error = -EAGAIN;
 			break;
 		}
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
index 749a608c40b0..f75696f0ee2d 100644
--- a/drivers/tty/n_r3964.c
+++ b/drivers/tty/n_r3964.c
@@ -1085,7 +1085,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 		pMsg = remove_msg(pInfo, pClient);
 		if (pMsg == NULL) {
 			/* no messages available. */
-			if (file->f_flags & O_NONBLOCK) {
+			if (tty_io_nonblock(tty, file)) {
 				ret = -EAGAIN;
 				goto unlock;
 			}
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 3ad460219fd6..5dc9686697cf 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1702,7 +1702,7 @@ n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
 
 	down_read(&tty->termios_rwsem);
 
-	while (1) {
+	do {
 		/*
 		 * When PARMRK is set, each input char may take up to 3 chars
 		 * in the read buf; reduce the buffer space avail by 3x
@@ -1744,7 +1744,7 @@ n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
 			fp += n;
 		count -= n;
 		rcvd += n;
-	}
+	} while (!test_bit(TTY_LDISC_CHANGING, &tty->flags));
 
 	tty->receive_room = room;
 
@@ -2211,7 +2211,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 					break;
 				if (!timeout)
 					break;
-				if (file->f_flags & O_NONBLOCK) {
+				if (tty_io_nonblock(tty, file)) {
 					retval = -EAGAIN;
 					break;
 				}
@@ -2365,7 +2365,7 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 		}
 		if (!nr)
 			break;
-		if (file->f_flags & O_NONBLOCK) {
+		if (tty_io_nonblock(tty, file)) {
 			retval = -EAGAIN;
 			break;
 		}
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index 9db93f500b4e..a0ac16ee6575 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -15,6 +15,7 @@
 #include <linux/of_device.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
+#include <linux/sched.h>
 #include <linux/serdev.h>
 #include <linux/slab.h>
 
@@ -216,6 +217,21 @@ void serdev_device_write_wakeup(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
 
+/**
+ * serdev_device_write_buf() - write data asynchronously
+ * @serdev:	serdev device
+ * @buf:	data to be written
+ * @count:	number of bytes to write
+ *
+ * Write data to the device asynchronously.
+ *
+ * Note that any accepted data has only been buffered by the controller; use
+ * serdev_device_wait_until_sent() to make sure the controller write buffer
+ * has actually been emptied.
+ *
+ * Return: The number of bytes written (less than count if not enough room in
+ * the write buffer), or a negative errno on errors.
+ */
 int serdev_device_write_buf(struct serdev_device *serdev,
 			    const unsigned char *buf, size_t count)
 {
@@ -228,17 +244,42 @@ int serdev_device_write_buf(struct serdev_device *serdev,
 }
 EXPORT_SYMBOL_GPL(serdev_device_write_buf);
 
+/**
+ * serdev_device_write() - write data synchronously
+ * @serdev:	serdev device
+ * @buf:	data to be written
+ * @count:	number of bytes to write
+ * @timeout:	timeout in jiffies, or 0 to wait indefinitely
+ *
+ * Write data to the device synchronously by repeatedly calling
+ * serdev_device_write() until the controller has accepted all data (unless
+ * interrupted by a timeout or a signal).
+ *
+ * Note that any accepted data has only been buffered by the controller; use
+ * serdev_device_wait_until_sent() to make sure the controller write buffer
+ * has actually been emptied.
+ *
+ * Note that this function depends on serdev_device_write_wakeup() being
+ * called in the serdev driver write_wakeup() callback.
+ *
+ * Return: The number of bytes written (less than count if interrupted),
+ * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
+ * a negative errno on errors.
+ */
 int serdev_device_write(struct serdev_device *serdev,
 			const unsigned char *buf, size_t count,
-			unsigned long timeout)
+			long timeout)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;
+	int written = 0;
 	int ret;
 
-	if (!ctrl || !ctrl->ops->write_buf ||
-	    (timeout && !serdev->ops->write_wakeup))
+	if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
 		return -EINVAL;
 
+	if (timeout == 0)
+		timeout = MAX_SCHEDULE_TIMEOUT;
+
 	mutex_lock(&serdev->write_lock);
 	do {
 		reinit_completion(&serdev->write_comp);
@@ -247,14 +288,29 @@ int serdev_device_write(struct serdev_device *serdev,
 		if (ret < 0)
 			break;
 
+		written += ret;
 		buf += ret;
 		count -= ret;
 
-	} while (count &&
-		 (timeout = wait_for_completion_timeout(&serdev->write_comp,
-							timeout)));
+		if (count == 0)
+			break;
+
+		timeout = wait_for_completion_interruptible_timeout(&serdev->write_comp,
+								    timeout);
+	} while (timeout > 0);
 	mutex_unlock(&serdev->write_lock);
-	return ret < 0 ? ret : (count ? -ETIMEDOUT : 0);
+
+	if (ret < 0)
+		return ret;
+
+	if (timeout <= 0 && written == 0) {
+		if (timeout == -ERESTARTSYS)
+			return -ERESTARTSYS;
+		else
+			return -ETIMEDOUT;
+	}
+
+	return written;
 }
 EXPORT_SYMBOL_GPL(serdev_device_write);
 
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 435bec40dee6..0438d9a905ce 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -5,6 +5,10 @@
  *    Copyright (C) 2016 Jeremy Kerr <jk@ozlabs.org>, IBM Corp.
  *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
  */
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -293,7 +297,7 @@ static int aspeed_vuart_handle_irq(struct uart_port *port)
 	if (lsr & UART_LSR_THRE)
 		serial8250_tx_chars(up);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_unlock_and_check_sysrq(port, flags);
 
 	return 1;
 }
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 94f3e1c64490..189ab1212d9a 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -942,6 +942,21 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
 	return NULL;
 }
 
+static void serial_8250_overrun_backoff_work(struct work_struct *work)
+{
+	struct uart_8250_port *up =
+	    container_of(to_delayed_work(work), struct uart_8250_port,
+			 overrun_backoff);
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	up->ier |= UART_IER_RLSI | UART_IER_RDI;
+	up->port.read_status_mask |= UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
 /**
  *	serial8250_register_8250_port - register a serial port
  *	@up: serial port template
@@ -1056,6 +1071,16 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 			ret = 0;
 		}
 	}
+
+	/* Initialise interrupt backoff work if required */
+	if (up->overrun_backoff_time_ms > 0) {
+		uart->overrun_backoff_time_ms = up->overrun_backoff_time_ms;
+		INIT_DELAYED_WORK(&uart->overrun_backoff,
+				  serial_8250_overrun_backoff_work);
+	} else {
+		uart->overrun_backoff_time_ms = 0;
+	}
+
 	mutex_unlock(&serial_mutex);
 
 	return ret;
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index 6640a4c7ddd1..aa0e216d5ead 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -1,4 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/serial_reg.h>
 #include <linux/serial_8250.h>
 
@@ -45,8 +49,29 @@ int fsl8250_handle_irq(struct uart_port *port)
 
 	lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
 
-	if (lsr & (UART_LSR_DR | UART_LSR_BI))
+	/* Process incoming characters first */
+	if ((lsr & (UART_LSR_DR | UART_LSR_BI)) &&
+	    (up->ier & (UART_IER_RLSI | UART_IER_RDI))) {
 		lsr = serial8250_rx_chars(up, lsr);
+	}
+
+	/* Stop processing interrupts on input overrun */
+	if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
+		unsigned long delay;
+
+		up->ier = port->serial_in(port, UART_IER);
+		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
+			port->ops->stop_rx(port);
+		} else {
+			/* Keep restarting the timer until
+			 * the input overrun subsides.
+			 */
+			cancel_delayed_work(&up->overrun_backoff);
+		}
+
+		delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
+		schedule_delayed_work(&up->overrun_backoff, delay);
+	}
 
 	serial8250_modem_status(up);
 
@@ -54,7 +79,7 @@ int fsl8250_handle_irq(struct uart_port *port)
 		serial8250_tx_chars(up);
 
 	up->lsr_saved_flags = orig_lsr;
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_unlock_and_check_sysrq(&up->port, flags);
 	return 1;
 }
 EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index c3f933d10295..e2c407656fa6 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -14,6 +14,10 @@
 #include <linux/pm_runtime.h>
 #include <linux/serial_8250.h>
 #include <linux/serial_reg.h>
+#include <linux/console.h>
+#include <linux/dma-mapping.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
 
 #include "8250.h"
 
@@ -22,12 +26,172 @@
 #define UART_MTK_SAMPLE_POINT	0x0b	/* Sample point register */
 #define MTK_UART_RATE_FIX	0x0d	/* UART Rate Fix Register */
 
+#define MTK_UART_DMA_EN		0x13	/* DMA Enable register */
+#define MTK_UART_DMA_EN_TX	0x2
+#define MTK_UART_DMA_EN_RX	0x5
+
+#define MTK_UART_TX_SIZE	UART_XMIT_SIZE
+#define MTK_UART_RX_SIZE	0x8000
+#define MTK_UART_TX_TRIGGER	1
+#define MTK_UART_RX_TRIGGER	MTK_UART_RX_SIZE
+
+#ifdef CONFIG_SERIAL_8250_DMA
+enum dma_rx_status {
+	DMA_RX_START = 0,
+	DMA_RX_RUNNING = 1,
+	DMA_RX_SHUTDOWN = 2,
+};
+#endif
+
 struct mtk8250_data {
 	int			line;
+	unsigned int		rx_pos;
 	struct clk		*uart_clk;
 	struct clk		*bus_clk;
+	struct uart_8250_dma	*dma;
+#ifdef CONFIG_SERIAL_8250_DMA
+	enum dma_rx_status	rx_status;
+#endif
 };
 
+#ifdef CONFIG_SERIAL_8250_DMA
+static void mtk8250_rx_dma(struct uart_8250_port *up);
+
+static void mtk8250_dma_rx_complete(void *param)
+{
+	struct uart_8250_port *up = param;
+	struct uart_8250_dma *dma = up->dma;
+	struct mtk8250_data *data = up->port.private_data;
+	struct tty_port *tty_port = &up->port.state->port;
+	struct dma_tx_state state;
+	unsigned char *ptr;
+	int copied;
+
+	dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
+				dma->rx_size, DMA_FROM_DEVICE);
+
+	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+
+	if (data->rx_status == DMA_RX_SHUTDOWN)
+		return;
+
+	if ((data->rx_pos + state.residue) <= dma->rx_size) {
+		ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+		copied = tty_insert_flip_string(tty_port, ptr, state.residue);
+	} else {
+		ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+		copied = tty_insert_flip_string(tty_port, ptr,
+						dma->rx_size - data->rx_pos);
+		ptr = (unsigned char *)(dma->rx_buf);
+		copied += tty_insert_flip_string(tty_port, ptr,
+				data->rx_pos + state.residue - dma->rx_size);
+	}
+	up->port.icount.rx += copied;
+
+	tty_flip_buffer_push(tty_port);
+
+	mtk8250_rx_dma(up);
+}
+
+static void mtk8250_rx_dma(struct uart_8250_port *up)
+{
+	struct uart_8250_dma *dma = up->dma;
+	struct mtk8250_data *data = up->port.private_data;
+	struct dma_async_tx_descriptor	*desc;
+	struct dma_tx_state	 state;
+
+	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
+					   dma->rx_size, DMA_DEV_TO_MEM,
+					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		pr_err("failed to prepare rx slave single\n");
+		return;
+	}
+
+	desc->callback = mtk8250_dma_rx_complete;
+	desc->callback_param = up;
+
+	dma->rx_cookie = dmaengine_submit(desc);
+
+	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+	data->rx_pos = state.residue;
+
+	dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
+				   dma->rx_size, DMA_FROM_DEVICE);
+
+	dma_async_issue_pending(dma->rxchan);
+}
+
+static void mtk8250_dma_enable(struct uart_8250_port *up)
+{
+	struct uart_8250_dma *dma = up->dma;
+	struct mtk8250_data *data = up->port.private_data;
+	int lcr = serial_in(up, UART_LCR);
+
+	if (data->rx_status != DMA_RX_START)
+		return;
+
+	dma->rxconf.direction		= DMA_DEV_TO_MEM;
+	dma->rxconf.src_addr_width	= dma->rx_size / 1024;
+	dma->rxconf.src_addr		= dma->rx_addr;
+
+	dma->txconf.direction		= DMA_MEM_TO_DEV;
+	dma->txconf.dst_addr_width	= MTK_UART_TX_SIZE / 1024;
+	dma->txconf.dst_addr		= dma->tx_addr;
+
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+		UART_FCR_CLEAR_XMIT);
+	serial_out(up, MTK_UART_DMA_EN,
+		   MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
+
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, UART_EFR_ECB);
+	serial_out(up, UART_LCR, lcr);
+
+	if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
+		pr_err("failed to configure rx dma channel\n");
+	if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
+		pr_err("failed to configure tx dma channel\n");
+
+	data->rx_status = DMA_RX_RUNNING;
+	data->rx_pos = 0;
+	mtk8250_rx_dma(up);
+}
+#endif
+
+static int mtk8250_startup(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct mtk8250_data *data = port->private_data;
+
+	/* disable DMA for console */
+	if (uart_console(port))
+		up->dma = NULL;
+
+	if (up->dma) {
+		data->rx_status = DMA_RX_START;
+		uart_circ_clear(&port->state->xmit);
+	}
+#endif
+	memset(&port->icount, 0, sizeof(port->icount));
+
+	return serial8250_do_startup(port);
+}
+
+static void mtk8250_shutdown(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct mtk8250_data *data = port->private_data;
+
+	if (up->dma)
+		data->rx_status = DMA_RX_SHUTDOWN;
+#endif
+
+	return serial8250_do_shutdown(port);
+}
+
 static void
 mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 			struct ktermios *old)
@@ -36,6 +200,17 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned long flags;
 	unsigned int baud, quot;
 
+#ifdef CONFIG_SERIAL_8250_DMA
+	if (up->dma) {
+		if (uart_console(port)) {
+			devm_kfree(up->port.dev, up->dma);
+			up->dma = NULL;
+		} else {
+			mtk8250_dma_enable(up);
+		}
+	}
+#endif
+
 	serial8250_do_set_termios(port, termios, old);
 
 	/*
@@ -143,9 +318,20 @@ mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 		pm_runtime_put_sync_suspend(port->dev);
 }
 
+#ifdef CONFIG_SERIAL_8250_DMA
+static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
+{
+	return false;
+}
+#endif
+
 static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 			   struct mtk8250_data *data)
 {
+#ifdef CONFIG_SERIAL_8250_DMA
+	int dmacnt;
+#endif
+
 	data->uart_clk = devm_clk_get(&pdev->dev, "baud");
 	if (IS_ERR(data->uart_clk)) {
 		/*
@@ -162,7 +348,23 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 	}
 
 	data->bus_clk = devm_clk_get(&pdev->dev, "bus");
-	return PTR_ERR_OR_ZERO(data->bus_clk);
+	if (IS_ERR(data->bus_clk))
+		return PTR_ERR(data->bus_clk);
+
+	data->dma = NULL;
+#ifdef CONFIG_SERIAL_8250_DMA
+	dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
+	if (dmacnt == 2) {
+		data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
+					 GFP_KERNEL);
+		data->dma->fn = mtk8250_dma_filter;
+		data->dma->rx_size = MTK_UART_RX_SIZE;
+		data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
+		data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
+	}
+#endif
+
+	return 0;
 }
 
 static int mtk8250_probe(struct platform_device *pdev)
@@ -204,8 +406,14 @@ static int mtk8250_probe(struct platform_device *pdev)
 	uart.port.iotype = UPIO_MEM32;
 	uart.port.regshift = 2;
 	uart.port.private_data = data;
+	uart.port.shutdown = mtk8250_shutdown;
+	uart.port.startup = mtk8250_startup;
 	uart.port.set_termios = mtk8250_set_termios;
 	uart.port.uartclk = clk_get_rate(data->uart_clk);
+#ifdef CONFIG_SERIAL_8250_DMA
+	if (data->dma)
+		uart.dma = data->dma;
+#endif
 
 	/* Disable Rate Fix function */
 	writel(0x0, uart.port.membase +
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 877fd7f8a8ed..a1a85805d010 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -240,6 +240,11 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	if (of_property_read_bool(ofdev->dev.of_node, "auto-flow-control"))
 		port8250.capabilities |= UART_CAP_AFE;
 
+	if (of_property_read_u32(ofdev->dev.of_node,
+			"overrun-throttle-ms",
+			&port8250.overrun_backoff_time_ms) != 0)
+		port8250.overrun_backoff_time_ms = 0;
+
 	ret = serial8250_register_8250_port(&port8250);
 	if (ret < 0)
 		goto err_dispose;
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index a019286f8bb6..ad7ba7d0f28d 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -8,6 +8,10 @@
  *
  */
 
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -1085,7 +1089,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
 		}
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_unlock_and_check_sysrq(port, flags);
 	serial8250_rpm_put(up);
 	return 1;
 }
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3f779d25ec0c..d2f3310abe54 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1736,7 +1736,7 @@ void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
 		else if (lsr & UART_LSR_FE)
 			flag = TTY_FRAME;
 	}
-	if (uart_handle_sysrq_char(port, ch))
+	if (uart_prepare_sysrq_char(port, ch))
 		return;
 
 	uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
@@ -1878,7 +1878,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 	if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE))
 		serial8250_tx_chars(up);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_unlock_and_check_sysrq(port, flags);
 	return 1;
 }
 EXPORT_SYMBOL_GPL(serial8250_handle_irq);
@@ -3239,9 +3239,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
 
 	serial8250_rpm_get(up);
 
-	if (port->sysrq)
-		locked = 0;
-	else if (oops_in_progress)
+	if (oops_in_progress)
 		locked = spin_trylock_irqsave(&port->lock, flags);
 	else
 		spin_lock_irqsave(&port->lock, flags);
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index ebd33c0232e6..89ade213a1a9 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2780,6 +2780,7 @@ static struct platform_driver arm_sbsa_uart_platform_driver = {
 		.name	= "sbsa-uart",
 		.of_match_table = of_match_ptr(sbsa_uart_of_match),
 		.acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match),
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
 	},
 };
 
@@ -2808,6 +2809,7 @@ static struct amba_driver pl011_driver = {
 	.drv = {
 		.name	= "uart-pl011",
 		.pm	= &pl011_dev_pm_ops,
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
 	},
 	.id_table	= pl011_ids,
 	.probe		= pl011_probe,
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 00c220e4f43c..241a48e5052c 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1479,6 +1479,8 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
 			else
 				cr1 &= ~UARTCR1_PT;
 		}
+	} else {
+		cr1 &= ~UARTCR1_PE;
 	}
 
 	/* ask the core to calculate the divisor */
@@ -1682,7 +1684,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 			ctrl &= ~UARTCTRL_PE;
 			ctrl |= UARTCTRL_M;
 		} else {
-			ctrl |= UARTCR1_PE;
+			ctrl |= UARTCTRL_PE;
 			if ((termios->c_cflag & CSIZE) == CS8)
 				ctrl |= UARTCTRL_M;
 			if (termios->c_cflag & PARODD)
@@ -1690,6 +1692,8 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 			else
 				ctrl &= ~UARTCTRL_PT;
 		}
+	} else {
+		ctrl &= ~UARTCTRL_PE;
 	}
 
 	/* ask the core to calculate the divisor */
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index d4e051b578f6..dff75dc94731 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -2064,7 +2064,7 @@ imx_uart_console_setup(struct console *co, char *options)
 
 	retval = clk_prepare(sport->clk_per);
 	if (retval)
-		clk_disable_unprepare(sport->clk_ipg);
+		clk_unprepare(sport->clk_ipg);
 
 error_console:
 	return retval;
diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 044128277248..e052b69ceb98 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -8,24 +8,23 @@
  * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
  */
 
-#include <linux/slab.h>
-#include <linux/ioport.h>
-#include <linux/init.h>
+#include <linux/clk.h>
 #include <linux/console.h>
-#include <linux/sysrq.h>
 #include <linux/device.h>
-#include <linux/tty.h>
-#include <linux/tty_flip.h>
-#include <linux/serial_core.h>
-#include <linux/serial.h>
-#include <linux/of_platform.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/lantiq.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
-#include <linux/io.h>
-#include <linux/clk.h>
-#include <linux/gpio.h>
-
-#include <lantiq_soc.h>
+#include <linux/of_platform.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
 
 #define PORT_LTQ_ASC		111
 #define MAXPORTS		2
@@ -105,7 +104,7 @@ static DEFINE_SPINLOCK(ltq_asc_lock);
 struct ltq_uart_port {
 	struct uart_port	port;
 	/* clock used to derive divider */
-	struct clk		*fpiclk;
+	struct clk		*freqclk;
 	/* clock gating of the ASC core */
 	struct clk		*clk;
 	unsigned int		tx_irq;
@@ -113,6 +112,13 @@ struct ltq_uart_port {
 	unsigned int		err_irq;
 };
 
+static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
+{
+	u32 tmp = readl(reg);
+
+	writel((tmp & ~clear) | set, reg);
+}
+
 static inline struct
 ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
 {
@@ -138,7 +144,7 @@ lqasc_start_tx(struct uart_port *port)
 static void
 lqasc_stop_rx(struct uart_port *port)
 {
-	ltq_w32(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
+	writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
 }
 
 static int
@@ -147,11 +153,11 @@ lqasc_rx_chars(struct uart_port *port)
 	struct tty_port *tport = &port->state->port;
 	unsigned int ch = 0, rsr = 0, fifocnt;
 
-	fifocnt = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_RXFFLMASK;
+	fifocnt = readl(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_RXFFLMASK;
 	while (fifocnt--) {
 		u8 flag = TTY_NORMAL;
-		ch = ltq_r8(port->membase + LTQ_ASC_RBUF);
-		rsr = (ltq_r32(port->membase + LTQ_ASC_STATE)
+		ch = readb(port->membase + LTQ_ASC_RBUF);
+		rsr = (readl(port->membase + LTQ_ASC_STATE)
 			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
 		tty_flip_buffer_push(tport);
 		port->icount.rx++;
@@ -163,16 +169,16 @@ lqasc_rx_chars(struct uart_port *port)
 		if (rsr & ASCSTATE_ANY) {
 			if (rsr & ASCSTATE_PE) {
 				port->icount.parity++;
-				ltq_w32_mask(0, ASCWHBSTATE_CLRPE,
+				asc_update_bits(0, ASCWHBSTATE_CLRPE,
 					port->membase + LTQ_ASC_WHBSTATE);
 			} else if (rsr & ASCSTATE_FE) {
 				port->icount.frame++;
-				ltq_w32_mask(0, ASCWHBSTATE_CLRFE,
+				asc_update_bits(0, ASCWHBSTATE_CLRFE,
 					port->membase + LTQ_ASC_WHBSTATE);
 			}
 			if (rsr & ASCSTATE_ROE) {
 				port->icount.overrun++;
-				ltq_w32_mask(0, ASCWHBSTATE_CLRROE,
+				asc_update_bits(0, ASCWHBSTATE_CLRROE,
 					port->membase + LTQ_ASC_WHBSTATE);
 			}
 
@@ -211,10 +217,10 @@ lqasc_tx_chars(struct uart_port *port)
 		return;
 	}
 
-	while (((ltq_r32(port->membase + LTQ_ASC_FSTAT) &
+	while (((readl(port->membase + LTQ_ASC_FSTAT) &
 		ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
 		if (port->x_char) {
-			ltq_w8(port->x_char, port->membase + LTQ_ASC_TBUF);
+			writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
 			port->icount.tx++;
 			port->x_char = 0;
 			continue;
@@ -223,7 +229,7 @@ lqasc_tx_chars(struct uart_port *port)
 		if (uart_circ_empty(xmit))
 			break;
 
-		ltq_w8(port->state->xmit.buf[port->state->xmit.tail],
+		writeb(port->state->xmit.buf[port->state->xmit.tail],
 			port->membase + LTQ_ASC_TBUF);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		port->icount.tx++;
@@ -239,7 +245,7 @@ lqasc_tx_int(int irq, void *_port)
 	unsigned long flags;
 	struct uart_port *port = (struct uart_port *)_port;
 	spin_lock_irqsave(&ltq_asc_lock, flags);
-	ltq_w32(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
+	writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
 	lqasc_start_tx(port);
 	return IRQ_HANDLED;
@@ -252,7 +258,7 @@ lqasc_err_int(int irq, void *_port)
 	struct uart_port *port = (struct uart_port *)_port;
 	spin_lock_irqsave(&ltq_asc_lock, flags);
 	/* clear any pending interrupts */
-	ltq_w32_mask(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
+	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
 		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
 	return IRQ_HANDLED;
@@ -264,7 +270,7 @@ lqasc_rx_int(int irq, void *_port)
 	unsigned long flags;
 	struct uart_port *port = (struct uart_port *)_port;
 	spin_lock_irqsave(&ltq_asc_lock, flags);
-	ltq_w32(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
+	writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
 	lqasc_rx_chars(port);
 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
 	return IRQ_HANDLED;
@@ -274,7 +280,7 @@ static unsigned int
 lqasc_tx_empty(struct uart_port *port)
 {
 	int status;
-	status = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFFLMASK;
+	status = readl(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFFLMASK;
 	return status ? 0 : TIOCSER_TEMT;
 }
 
@@ -301,18 +307,18 @@ lqasc_startup(struct uart_port *port)
 	int retval;
 
 	if (!IS_ERR(ltq_port->clk))
-		clk_enable(ltq_port->clk);
-	port->uartclk = clk_get_rate(ltq_port->fpiclk);
+		clk_prepare_enable(ltq_port->clk);
+	port->uartclk = clk_get_rate(ltq_port->freqclk);
 
-	ltq_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
+	asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
 		port->membase + LTQ_ASC_CLC);
 
-	ltq_w32(0, port->membase + LTQ_ASC_PISEL);
-	ltq_w32(
+	writel(0, port->membase + LTQ_ASC_PISEL);
+	writel(
 		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
 		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
 		port->membase + LTQ_ASC_TXFCON);
-	ltq_w32(
+	writel(
 		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
 		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
 		port->membase + LTQ_ASC_RXFCON);
@@ -320,7 +326,7 @@ lqasc_startup(struct uart_port *port)
 	 * setting enable bits
 	 */
 	wmb();
-	ltq_w32_mask(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
+	asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
 		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
 
 	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
@@ -344,7 +350,7 @@ lqasc_startup(struct uart_port *port)
 		goto err2;
 	}
 
-	ltq_w32(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
+	writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
 		port->membase + LTQ_ASC_IRNREN);
 	return 0;
 
@@ -363,13 +369,13 @@ lqasc_shutdown(struct uart_port *port)
 	free_irq(ltq_port->rx_irq, port);
 	free_irq(ltq_port->err_irq, port);
 
-	ltq_w32(0, port->membase + LTQ_ASC_CON);
-	ltq_w32_mask(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
+	writel(0, port->membase + LTQ_ASC_CON);
+	asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
 		port->membase + LTQ_ASC_RXFCON);
-	ltq_w32_mask(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
+	asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
 		port->membase + LTQ_ASC_TXFCON);
 	if (!IS_ERR(ltq_port->clk))
-		clk_disable(ltq_port->clk);
+		clk_disable_unprepare(ltq_port->clk);
 }
 
 static void
@@ -438,7 +444,7 @@ lqasc_set_termios(struct uart_port *port,
 	spin_lock_irqsave(&ltq_asc_lock, flags);
 
 	/* set up CON */
-	ltq_w32_mask(0, con, port->membase + LTQ_ASC_CON);
+	asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
 
 	/* Set baud rate - take a divider of 2 into account */
 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
@@ -446,22 +452,22 @@ lqasc_set_termios(struct uart_port *port,
 	divisor = divisor / 2 - 1;
 
 	/* disable the baudrate generator */
-	ltq_w32_mask(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
+	asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
 
 	/* make sure the fractional divider is off */
-	ltq_w32_mask(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
+	asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
 
 	/* set up to use divisor of 2 */
-	ltq_w32_mask(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
+	asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
 
 	/* now we can write the new baudrate into the register */
-	ltq_w32(divisor, port->membase + LTQ_ASC_BG);
+	writel(divisor, port->membase + LTQ_ASC_BG);
 
 	/* turn the baudrate generator back on */
-	ltq_w32_mask(0, ASCCON_R, port->membase + LTQ_ASC_CON);
+	asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
 
 	/* enable rx */
-	ltq_w32(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
+	writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
 
 	spin_unlock_irqrestore(&ltq_asc_lock, flags);
 
@@ -572,10 +578,10 @@ lqasc_console_putchar(struct uart_port *port, int ch)
 		return;
 
 	do {
-		fifofree = (ltq_r32(port->membase + LTQ_ASC_FSTAT)
+		fifofree = (readl(port->membase + LTQ_ASC_FSTAT)
 			& ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
 	} while (fifofree == 0);
-	ltq_w8(ch, port->membase + LTQ_ASC_TBUF);
+	writeb(ch, port->membase + LTQ_ASC_TBUF);
 }
 
 static void lqasc_serial_port_write(struct uart_port *port, const char *s,
@@ -623,9 +629,9 @@ lqasc_console_setup(struct console *co, char *options)
 	port = &ltq_port->port;
 
 	if (!IS_ERR(ltq_port->clk))
-		clk_enable(ltq_port->clk);
+		clk_prepare_enable(ltq_port->clk);
 
-	port->uartclk = clk_get_rate(ltq_port->fpiclk);
+	port->uartclk = clk_get_rate(ltq_port->freqclk);
 
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
@@ -688,7 +694,7 @@ lqasc_probe(struct platform_device *pdev)
 	struct ltq_uart_port *ltq_port;
 	struct uart_port *port;
 	struct resource *mmres, irqres[3];
-	int line = 0;
+	int line;
 	int ret;
 
 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -699,9 +705,20 @@ lqasc_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	/* check if this is the console port */
-	if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC))
-		line = 1;
+	/* get serial id */
+	line = of_alias_get_id(node, "serial");
+	if (line < 0) {
+		if (IS_ENABLED(CONFIG_LANTIQ)) {
+			if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
+				line = 0;
+			else
+				line = 1;
+		} else {
+			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
+				line);
+			return line;
+		}
+	}
 
 	if (lqasc_port[line]) {
 		dev_err(&pdev->dev, "port %d already allocated\n", line);
@@ -726,14 +743,22 @@ lqasc_probe(struct platform_device *pdev)
 	port->irq	= irqres[0].start;
 	port->mapbase	= mmres->start;
 
-	ltq_port->fpiclk = clk_get_fpi();
-	if (IS_ERR(ltq_port->fpiclk)) {
+	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
+		ltq_port->freqclk = clk_get_fpi();
+	else
+		ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
+
+
+	if (IS_ERR(ltq_port->freqclk)) {
 		pr_err("failed to get fpi clk\n");
 		return -ENOENT;
 	}
 
 	/* not all asc ports have clock gates, lets ignore the return code */
-	ltq_port->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
+		ltq_port->clk = clk_get(&pdev->dev, NULL);
+	else
+		ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
 
 	ltq_port->tx_irq = irqres[0].start;
 	ltq_port->rx_irq = irqres[1].start;
@@ -759,7 +784,7 @@ static struct platform_driver lqasc_driver = {
 	},
 };
 
-int __init
+static int __init
 init_lqasc(void)
 {
 	int ret;
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 3db48fcd6068..4f479841769a 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -833,12 +833,9 @@ static void max310x_wq_proc(struct work_struct *ws)
 
 static unsigned int max310x_tx_empty(struct uart_port *port)
 {
-	unsigned int lvl, sts;
+	u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
 
-	lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
-	sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
-
-	return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
+	return lvl ? 0 : TIOCSER_TEMT;
 }
 
 static unsigned int max310x_get_mctrl(struct uart_port *port)
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index 170e446a2f62..231f751d1ef4 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -72,6 +72,8 @@
 #define  BRDV_BAUD_MASK         0x3FF
 
 #define UART_OSAMP		0x14
+#define  OSAMP_DEFAULT_DIVISOR	16
+#define  OSAMP_DIVISORS_MASK	0x3F3F3F3F
 
 #define MVEBU_NR_UARTS		2
 
@@ -444,25 +446,34 @@ static void mvebu_uart_shutdown(struct uart_port *port)
 static int mvebu_uart_baud_rate_set(struct uart_port *port, unsigned int baud)
 {
 	struct mvebu_uart *mvuart = to_mvuart(port);
-	unsigned int baud_rate_div;
-	u32 brdv;
+	unsigned int d_divisor, m_divisor;
+	u32 brdv, osamp;
 
 	if (IS_ERR(mvuart->clk))
 		return -PTR_ERR(mvuart->clk);
 
 	/*
-	 * The UART clock is divided by the value of the divisor to generate
-	 * UCLK_OUT clock, which is 16 times faster than the baudrate.
-	 * This prescaler can achieve all standard baudrates until 230400.
-	 * Higher baudrates could be achieved for the extended UART by using the
-	 * programmable oversampling stack (also called fractional divisor).
+	 * The baudrate is derived from the UART clock thanks to two divisors:
+	 *   > D ("baud generator"): can divide the clock from 2 to 2^10 - 1.
+	 *   > M ("fractional divisor"): allows a better accuracy for
+	 *     baudrates higher than 230400.
+	 *
+	 * As the derivation of M is rather complicated, the code sticks to its
+	 * default value (x16) when all the prescalers are zeroed, and only
+	 * makes use of D to configure the desired baudrate.
 	 */
-	baud_rate_div = DIV_ROUND_UP(port->uartclk, baud * 16);
+	m_divisor = OSAMP_DEFAULT_DIVISOR;
+	d_divisor = DIV_ROUND_UP(port->uartclk, baud * m_divisor);
+
 	brdv = readl(port->membase + UART_BRDV);
 	brdv &= ~BRDV_BAUD_MASK;
-	brdv |= baud_rate_div;
+	brdv |= d_divisor;
 	writel(brdv, port->membase + UART_BRDV);
 
+	osamp = readl(port->membase + UART_OSAMP);
+	osamp &= ~OSAMP_DIVISORS_MASK;
+	writel(osamp, port->membase + UART_OSAMP);
+
 	return 0;
 }
 
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index cb85002a10d8..9ed121f08a54 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -933,7 +933,6 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
 	struct scatterlist *sg;
 	int nent;
 	int fifo_size;
-	int tx_empty;
 	struct dma_async_tx_descriptor *desc;
 	int num;
 	int i;
@@ -958,11 +957,9 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
 	}
 
 	fifo_size = max(priv->fifo_size, 1);
-	tx_empty = 1;
 	if (pop_tx_x(priv, xmit->buf)) {
 		pch_uart_hal_write(priv, xmit->buf, 1);
 		port->icount.tx++;
-		tx_empty = 0;
 		fifo_size--;
 	}
 
diff --git a/drivers/tty/serial/pic32_uart.c b/drivers/tty/serial/pic32_uart.c
index fd80d999308d..0bdf1687983f 100644
--- a/drivers/tty/serial/pic32_uart.c
+++ b/drivers/tty/serial/pic32_uart.c
@@ -919,6 +919,7 @@ static struct platform_driver pic32_uart_platform_driver = {
 	.driver		= {
 		.name	= PIC32_DEV_NAME,
 		.of_match_table	= of_match_ptr(pic32_serial_dt_ids),
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_PIC32),
 	},
 };
 
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index a9d40988e1c8..bcb5bf70534e 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -1648,9 +1648,9 @@ static int __init pmz_probe(void)
 		 */
 		node_a = node_b = NULL;
 		for (np = NULL; (np = of_get_next_child(node_p, np)) != NULL;) {
-			if (strncmp(np->name, "ch-a", 4) == 0)
+			if (of_node_name_prefix(np, "ch-a"))
 				node_a = of_node_get(np);
-			else if (strncmp(np->name, "ch-b", 4) == 0)
+			else if (of_node_name_prefix(np, "ch-b"))
 				node_b = of_node_get(np);
 		}
 		if (!node_a && !node_b) {
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index d3b5261ee80a..a72d6d9fb983 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1,6 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
 
+#if defined(CONFIG_SERIAL_QCOM_GENI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+# define SUPPORT_SYSRQ
+#endif
+
 #include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/io.h>
@@ -89,9 +93,9 @@
 #define MAX_LOOPBACK_CFG	3
 
 #ifdef CONFIG_CONSOLE_POLL
-#define RX_BYTES_PW 1
+#define CONSOLE_RX_BYTES_PW 1
 #else
-#define RX_BYTES_PW 4
+#define CONSOLE_RX_BYTES_PW 4
 #endif
 
 struct qcom_geni_serial_port {
@@ -113,6 +117,8 @@ struct qcom_geni_serial_port {
 	u32 *rx_fifo;
 	u32 loopback;
 	bool brk;
+
+	unsigned int tx_remaining;
 };
 
 static const struct uart_ops qcom_geni_console_pops;
@@ -162,8 +168,7 @@ static struct qcom_geni_serial_port qcom_geni_uart_ports[GENI_UART_PORTS] = {
 static ssize_t loopback_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
 
 	return snprintf(buf, sizeof(u32), "%d\n", port->loopback);
 }
@@ -172,8 +177,7 @@ static ssize_t loopback_store(struct device *dev,
 				struct device_attribute *attr, const char *buf,
 				size_t size)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct qcom_geni_serial_port *port = platform_get_drvdata(pdev);
+	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
 	u32 loopback;
 
 	if (kstrtoint(buf, 0, &loopback) || loopback > MAX_LOOPBACK_CFG) {
@@ -435,6 +439,8 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
 	struct qcom_geni_serial_port *port;
 	bool locked = true;
 	unsigned long flags;
+	u32 geni_status;
+	u32 irq_en;
 
 	WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS);
 
@@ -448,6 +454,8 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
 	else
 		spin_lock_irqsave(&uport->lock, flags);
 
+	geni_status = readl_relaxed(uport->membase + SE_GENI_STATUS);
+
 	/* Cancel the current write to log the fault */
 	if (!locked) {
 		geni_se_cancel_m_cmd(&port->se);
@@ -461,9 +469,26 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s,
 		}
 		writel_relaxed(M_CMD_CANCEL_EN, uport->membase +
 							SE_GENI_M_IRQ_CLEAR);
+	} else if ((geni_status & M_GENI_CMD_ACTIVE) && !port->tx_remaining) {
+		/*
+		 * It seems we can't interrupt existing transfers if all data
+		 * has been sent, in which case we need to look for done first.
+		 */
+		qcom_geni_serial_poll_tx_done(uport);
+
+		if (uart_circ_chars_pending(&uport->state->xmit)) {
+			irq_en = readl_relaxed(uport->membase +
+					SE_GENI_M_IRQ_EN);
+			writel_relaxed(irq_en | M_TX_FIFO_WATERMARK_EN,
+					uport->membase + SE_GENI_M_IRQ_EN);
+		}
 	}
 
 	__qcom_geni_serial_console_write(uport, s, count);
+
+	if (port->tx_remaining)
+		qcom_geni_serial_setup_tx(uport, port->tx_remaining);
+
 	if (locked)
 		spin_unlock_irqrestore(&uport->lock, flags);
 }
@@ -495,7 +520,8 @@ static int handle_rx_console(struct uart_port *uport, u32 bytes, bool drop)
 					continue;
 			}
 
-			sysrq = uart_handle_sysrq_char(uport, buf[c]);
+			sysrq = uart_prepare_sysrq_char(uport, buf[c]);
+
 			if (!sysrq)
 				tty_insert_flip_char(tport, buf[c], TTY_NORMAL);
 		}
@@ -694,40 +720,51 @@ static void qcom_geni_serial_handle_rx(struct uart_port *uport, bool drop)
 	port->handle_rx(uport, total_bytes, drop);
 }
 
-static void qcom_geni_serial_handle_tx(struct uart_port *uport)
+static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
+		bool active)
 {
 	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
 	struct circ_buf *xmit = &uport->state->xmit;
 	size_t avail;
 	size_t remaining;
+	size_t pending;
 	int i;
 	u32 status;
+	u32 irq_en;
 	unsigned int chunk;
 	int tail;
-	u32 irq_en;
 
-	chunk = uart_circ_chars_pending(xmit);
 	status = readl_relaxed(uport->membase + SE_GENI_TX_FIFO_STATUS);
-	/* Both FIFO and framework buffer are drained */
-	if (!chunk && !status) {
+
+	/* Complete the current tx command before taking newly added data */
+	if (active)
+		pending = port->tx_remaining;
+	else
+		pending = uart_circ_chars_pending(xmit);
+
+	/* All data has been transmitted and acknowledged as received */
+	if (!pending && !status && done) {
 		qcom_geni_serial_stop_tx(uport);
 		goto out_write_wakeup;
 	}
 
-	if (!uart_console(uport)) {
-		irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
-		irq_en &= ~(M_TX_FIFO_WATERMARK_EN);
-		writel_relaxed(0, uport->membase + SE_GENI_TX_WATERMARK_REG);
-		writel_relaxed(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
-	}
+	avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
+	avail *= port->tx_bytes_pw;
 
-	avail = (port->tx_fifo_depth - port->tx_wm) * port->tx_bytes_pw;
 	tail = xmit->tail;
-	chunk = min3((size_t)chunk, (size_t)(UART_XMIT_SIZE - tail), avail);
+	chunk = min(avail, pending);
 	if (!chunk)
 		goto out_write_wakeup;
 
-	qcom_geni_serial_setup_tx(uport, chunk);
+	if (!port->tx_remaining) {
+		qcom_geni_serial_setup_tx(uport, pending);
+		port->tx_remaining = pending;
+
+		irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
+		if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
+			writel_relaxed(irq_en | M_TX_FIFO_WATERMARK_EN,
+					uport->membase + SE_GENI_M_IRQ_EN);
+	}
 
 	remaining = chunk;
 	for (i = 0; i < chunk; ) {
@@ -737,21 +774,38 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport)
 
 		memset(buf, 0, ARRAY_SIZE(buf));
 		tx_bytes = min_t(size_t, remaining, port->tx_bytes_pw);
-		for (c = 0; c < tx_bytes ; c++)
-			buf[c] = xmit->buf[tail + c];
+
+		for (c = 0; c < tx_bytes ; c++) {
+			buf[c] = xmit->buf[tail++];
+			tail &= UART_XMIT_SIZE - 1;
+		}
 
 		iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);
 
 		i += tx_bytes;
-		tail += tx_bytes;
 		uport->icount.tx += tx_bytes;
 		remaining -= tx_bytes;
+		port->tx_remaining -= tx_bytes;
 	}
 
-	xmit->tail = tail & (UART_XMIT_SIZE - 1);
-	if (uart_console(uport))
-		qcom_geni_serial_poll_tx_done(uport);
+	xmit->tail = tail;
+
+	/*
+	 * The tx fifo watermark is level triggered and latched. Though we had
+	 * cleared it in qcom_geni_serial_isr it will have already reasserted
+	 * so we must clear it again here after our writes.
+	 */
+	writel_relaxed(M_TX_FIFO_WATERMARK_EN,
+			uport->membase + SE_GENI_M_IRQ_CLEAR);
+
 out_write_wakeup:
+	if (!port->tx_remaining) {
+		irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
+		if (irq_en & M_TX_FIFO_WATERMARK_EN)
+			writel_relaxed(irq_en & ~M_TX_FIFO_WATERMARK_EN,
+					uport->membase + SE_GENI_M_IRQ_EN);
+	}
+
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(uport);
 }
@@ -760,6 +814,7 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 {
 	unsigned int m_irq_status;
 	unsigned int s_irq_status;
+	unsigned int geni_status;
 	struct uart_port *uport = dev;
 	unsigned long flags;
 	unsigned int m_irq_en;
@@ -773,6 +828,7 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 	spin_lock_irqsave(&uport->lock, flags);
 	m_irq_status = readl_relaxed(uport->membase + SE_GENI_M_IRQ_STATUS);
 	s_irq_status = readl_relaxed(uport->membase + SE_GENI_S_IRQ_STATUS);
+	geni_status = readl_relaxed(uport->membase + SE_GENI_STATUS);
 	m_irq_en = readl_relaxed(uport->membase + SE_GENI_M_IRQ_EN);
 	writel_relaxed(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
 	writel_relaxed(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
@@ -785,9 +841,9 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 	}
 
-	if (m_irq_status & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN) &&
-	    m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
-		qcom_geni_serial_handle_tx(uport);
+	if (m_irq_status & m_irq_en & (M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN))
+		qcom_geni_serial_handle_tx(uport, m_irq_status & M_CMD_DONE_EN,
+					geni_status & M_GENI_CMD_ACTIVE);
 
 	if (s_irq_status & S_GP_IRQ_0_EN || s_irq_status & S_GP_IRQ_1_EN) {
 		if (s_irq_status & S_GP_IRQ_0_EN)
@@ -804,7 +860,8 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 		qcom_geni_serial_handle_rx(uport, drop_rx);
 
 out_unlock:
-	spin_unlock_irqrestore(&uport->lock, flags);
+	uart_unlock_and_check_sysrq(uport, flags);
+
 	return IRQ_HANDLED;
 }
 
@@ -853,11 +910,13 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport)
 	unsigned int rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT;
 	u32 proto;
 
-	if (uart_console(uport))
+	if (uart_console(uport)) {
 		port->tx_bytes_pw = 1;
-	else
+		port->rx_bytes_pw = CONSOLE_RX_BYTES_PW;
+	} else {
 		port->tx_bytes_pw = 4;
-	port->rx_bytes_pw = RX_BYTES_PW;
+		port->rx_bytes_pw = 4;
+	}
 
 	proto = geni_se_read_proto(&port->se);
 	if (proto != GENI_SE_UART) {
@@ -1322,49 +1381,25 @@ static int qcom_geni_serial_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static int __maybe_unused qcom_geni_serial_sys_suspend_noirq(struct device *dev)
+static int __maybe_unused qcom_geni_serial_sys_suspend(struct device *dev)
 {
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
 	struct uart_port *uport = &port->uport;
 
-	if (uart_console(uport)) {
-		uart_suspend_port(uport->private_data, uport);
-	} else {
-		struct uart_state *state = uport->state;
-		/*
-		 * If the port is open, deny system suspend.
-		 */
-		if (state->pm_state == UART_PM_STATE_ON)
-			return -EBUSY;
-	}
-
-	return 0;
+	return uart_suspend_port(uport->private_data, uport);
 }
 
-static int __maybe_unused qcom_geni_serial_sys_resume_noirq(struct device *dev)
+static int __maybe_unused qcom_geni_serial_sys_resume(struct device *dev)
 {
 	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
 	struct uart_port *uport = &port->uport;
 
-	if (uart_console(uport) &&
-			console_suspend_enabled && uport->suspended) {
-		uart_resume_port(uport->private_data, uport);
-		/*
-		 * uart_suspend_port() invokes port shutdown which in turn
-		 * frees the irq. uart_resume_port invokes port startup which
-		 * performs request_irq. The request_irq auto-enables the IRQ.
-		 * In addition, resume_noirq implicitly enables the IRQ and
-		 * leads to an unbalanced IRQ enable warning. Disable the IRQ
-		 * before returning so that the warning is suppressed.
-		 */
-		disable_irq(uport->irq);
-	}
-	return 0;
+	return uart_resume_port(uport->private_data, uport);
 }
 
 static const struct dev_pm_ops qcom_geni_serial_pm_ops = {
-	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend_noirq,
-					qcom_geni_serial_sys_resume_noirq)
+	SET_SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend,
+					qcom_geni_serial_sys_resume)
 };
 
 static const struct of_device_id qcom_geni_serial_match_table[] = {
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index da1bd4bba8a9..9fc3559f80d9 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1287,7 +1287,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 	 * Ask the core to calculate the divisor for us.
 	 */
 
-	baud = uart_get_baud_rate(port, termios, old, 0, 115200*8);
+	baud = uart_get_baud_rate(port, termios, old, 0, 3000000);
 	quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel);
 	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 		quot = port->custom_divisor;
@@ -1365,11 +1365,14 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
 	wr_regl(port, S3C2410_ULCON, ulcon);
 	wr_regl(port, S3C2410_UBRDIV, quot);
 
+	port->status &= ~UPSTAT_AUTOCTS;
+
 	umcon = rd_regl(port, S3C2410_UMCON);
 	if (termios->c_cflag & CRTSCTS) {
 		umcon |= S3C2410_UMCOM_AFC;
 		/* Disable RTS when RX FIFO contains 63 bytes */
 		umcon &= ~S3C2412_UMCON_AFC_8;
+		port->status = UPSTAT_AUTOCTS;
 	} else {
 		umcon &= ~S3C2410_UMCOM_AFC;
 	}
diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index 339befdd2f4d..68a24a14f6b7 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -12,6 +12,7 @@
 #endif
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
@@ -47,7 +48,6 @@
 #	define MR2_STOP1		(7 << 0)
 #	define MR2_STOP2		(0xf << 0)
 #define SCCNXP_SR_REG			(0x01)
-#define SCCNXP_CSR_REG			SCCNXP_SR_REG
 #	define SR_RXRDY			(1 << 0)
 #	define SR_FULL			(1 << 1)
 #	define SR_TXRDY			(1 << 2)
@@ -56,6 +56,8 @@
 #	define SR_PE			(1 << 5)
 #	define SR_FE			(1 << 6)
 #	define SR_BRK			(1 << 7)
+#define SCCNXP_CSR_REG			(SCCNXP_SR_REG)
+#	define CSR_TIMER_MODE		(0x0d)
 #define SCCNXP_CR_REG			(0x02)
 #	define CR_RX_ENABLE		(1 << 0)
 #	define CR_RX_DISABLE		(1 << 1)
@@ -82,9 +84,12 @@
 #	define IMR_RXRDY		(1 << 1)
 #	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
 #	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
+#define SCCNXP_CTPU_REG			(0x06)
+#define SCCNXP_CTPL_REG			(0x07)
 #define SCCNXP_IPR_REG			(0x0d)
 #define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
 #define SCCNXP_SOP_REG			(0x0e)
+#define SCCNXP_START_COUNTER_REG	SCCNXP_SOP_REG
 #define SCCNXP_ROP_REG			(0x0f)
 
 /* Route helpers */
@@ -103,6 +108,8 @@ struct sccnxp_chip {
 	unsigned long		freq_max;
 	unsigned int		flags;
 	unsigned int		fifosize;
+	/* Time between read/write cycles */
+	unsigned int		trwd;
 };
 
 struct sccnxp_port {
@@ -137,6 +144,7 @@ static const struct sccnxp_chip sc2681 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 200,
 };
 
 static const struct sccnxp_chip sc2691 = {
@@ -147,6 +155,7 @@ static const struct sccnxp_chip sc2691 = {
 	.freq_max	= 4000000,
 	.flags		= 0,
 	.fifosize	= 3,
+	.trwd		= 150,
 };
 
 static const struct sccnxp_chip sc2692 = {
@@ -157,6 +166,7 @@ static const struct sccnxp_chip sc2692 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 30,
 };
 
 static const struct sccnxp_chip sc2891 = {
@@ -167,6 +177,7 @@ static const struct sccnxp_chip sc2891 = {
 	.freq_max	= 8000000,
 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
 	.fifosize	= 16,
+	.trwd		= 27,
 };
 
 static const struct sccnxp_chip sc2892 = {
@@ -177,6 +188,7 @@ static const struct sccnxp_chip sc2892 = {
 	.freq_max	= 8000000,
 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
 	.fifosize	= 16,
+	.trwd		= 17,
 };
 
 static const struct sccnxp_chip sc28202 = {
@@ -187,6 +199,7 @@ static const struct sccnxp_chip sc28202 = {
 	.freq_max	= 50000000,
 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
 	.fifosize	= 256,
+	.trwd		= 10,
 };
 
 static const struct sccnxp_chip sc68681 = {
@@ -197,6 +210,7 @@ static const struct sccnxp_chip sc68681 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 200,
 };
 
 static const struct sccnxp_chip sc68692 = {
@@ -207,24 +221,36 @@ static const struct sccnxp_chip sc68692 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 200,
 };
 
-static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
+static u8 sccnxp_read(struct uart_port *port, u8 reg)
 {
-	return readb(port->membase + (reg << port->regshift));
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	u8 ret;
+
+	ret = readb(port->membase + (reg << port->regshift));
+
+	ndelay(s->chip->trwd);
+
+	return ret;
 }
 
-static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
+static void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
 {
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
 	writeb(v, port->membase + (reg << port->regshift));
+
+	ndelay(s->chip->trwd);
 }
 
-static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
+static u8 sccnxp_port_read(struct uart_port *port, u8 reg)
 {
 	return sccnxp_read(port, (port->line << 3) + reg);
 }
 
-static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
+static void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
 {
 	sccnxp_write(port, (port->line << 3) + reg, v);
 }
@@ -233,7 +259,7 @@ static int sccnxp_update_best_err(int a, int b, int *besterr)
 {
 	int err = abs(a - b);
 
-	if ((*besterr < 0) || (*besterr > err)) {
+	if (*besterr > err) {
 		*besterr = err;
 		return 0;
 	}
@@ -281,10 +307,22 @@ static const struct {
 static int sccnxp_set_baud(struct uart_port *port, int baud)
 {
 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
-	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
+	int div_std, tmp_baud, bestbaud = INT_MAX, besterr = INT_MAX;
 	struct sccnxp_chip *chip = s->chip;
 	u8 i, acr = 0, csr = 0, mr0 = 0;
 
+	/* Find divisor to load to the timer preset registers */
+	div_std = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * baud);
+	if ((div_std >= 2) && (div_std <= 0xffff)) {
+		bestbaud = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * div_std);
+		sccnxp_update_best_err(baud, bestbaud, &besterr);
+		csr = CSR_TIMER_MODE;
+		sccnxp_port_write(port, SCCNXP_CTPU_REG, div_std >> 8);
+		sccnxp_port_write(port, SCCNXP_CTPL_REG, div_std);
+		/* Issue start timer/counter command */
+		sccnxp_port_read(port, SCCNXP_START_COUNTER_REG);
+	}
+
 	/* Find best baud from table */
 	for (i = 0; baud_std[i].baud && besterr; i++) {
 		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index af2a29cfbbe9..d5269aaaf9b2 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -746,7 +746,7 @@ static void tegra_uart_stop_rx(struct uart_port *u)
 	if (!tup->rx_in_progress)
 		return;
 
-	tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */
+	tegra_uart_wait_sym_time(tup, 1); /* wait one character interval */
 
 	ier = tup->ier_shadow;
 	ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
@@ -887,7 +887,7 @@ static int tegra_uart_hw_init(struct tegra_uart_port *tup)
 	 *
 	 * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when
 	 * the DATA is sitting in the FIFO and couldn't be transferred to the
-	 * DMA as the DMA size alignment(4 bytes) is not met. EORD will be
+	 * DMA as the DMA size alignment (4 bytes) is not met. EORD will be
 	 * triggered when there is a pause of the incomming data stream for 4
 	 * characters long.
 	 *
@@ -1079,7 +1079,7 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	if (tup->rts_active)
 		set_rts(tup, false);
 
-	/* Clear all interrupts as configuration is going to be change */
+	/* Clear all interrupts as configuration is going to be changed */
 	tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
 	tegra_uart_read(tup, UART_IER);
 	tegra_uart_write(tup, 0, UART_IER);
@@ -1165,10 +1165,10 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	/* update the port timeout based on new settings */
 	uart_update_timeout(u, termios->c_cflag, baud);
 
-	/* Make sure all write has completed */
+	/* Make sure all writes have completed */
 	tegra_uart_read(tup, UART_IER);
 
-	/* Reenable interrupt */
+	/* Re-enable interrupt */
 	tegra_uart_write(tup, tup->ier_shadow, UART_IER);
 	tegra_uart_read(tup, UART_IER);
 
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index c439a5a1e6c0..d4cca5bdaf1c 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -205,10 +205,15 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
 	if (!state->xmit.buf) {
 		state->xmit.buf = (unsigned char *) page;
 		uart_circ_clear(&state->xmit);
+		uart_port_unlock(uport, flags);
 	} else {
+		uart_port_unlock(uport, flags);
+		/*
+		 * Do not free() the page under the port lock, see
+		 * uart_shutdown().
+		 */
 		free_page(page);
 	}
-	uart_port_unlock(uport, flags);
 
 	retval = uport->ops->startup(uport);
 	if (retval == 0) {
@@ -268,6 +273,7 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 	struct uart_port *uport = uart_port_check(state);
 	struct tty_port *port = &state->port;
 	unsigned long flags = 0;
+	char *xmit_buf = NULL;
 
 	/*
 	 * Set the TTY IO error marker
@@ -298,14 +304,18 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 	tty_port_set_suspended(port, 0);
 
 	/*
-	 * Free the transmit buffer page.
+	 * Do not free() the transmit buffer page under the port lock since
+	 * this can create various circular locking scenarios. For instance,
+	 * console driver may need to allocate/free a debug object, which
+	 * can endup in printk() recursion.
 	 */
 	uart_port_lock(state, flags);
-	if (state->xmit.buf) {
-		free_page((unsigned long)state->xmit.buf);
-		state->xmit.buf = NULL;
-	}
+	xmit_buf = state->xmit.buf;
+	state->xmit.buf = NULL;
 	uart_port_unlock(uport, flags);
+
+	if (xmit_buf)
+		free_page((unsigned long)xmit_buf);
 }
 
 /**
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index cc56cb3b3eca..8df0fd824520 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1331,7 +1331,7 @@ static void sci_tx_dma_release(struct sci_port *s)
 	dma_release_channel(chan);
 }
 
-static void sci_submit_rx(struct sci_port *s)
+static int sci_submit_rx(struct sci_port *s, bool port_lock_held)
 {
 	struct dma_chan *chan = s->chan_rx;
 	struct uart_port *port = &s->port;
@@ -1359,19 +1359,22 @@ static void sci_submit_rx(struct sci_port *s)
 	s->active_rx = s->cookie_rx[0];
 
 	dma_async_issue_pending(chan);
-	return;
+	return 0;
 
 fail:
+	/* Switch to PIO */
+	if (!port_lock_held)
+		spin_lock_irqsave(&port->lock, flags);
 	if (i)
 		dmaengine_terminate_async(chan);
 	for (i = 0; i < 2; i++)
 		s->cookie_rx[i] = -EINVAL;
-	s->active_rx = -EINVAL;
-	/* Switch to PIO */
-	spin_lock_irqsave(&port->lock, flags);
+	s->active_rx = 0;
 	s->chan_rx = NULL;
 	sci_start_rx(port);
-	spin_unlock_irqrestore(&port->lock, flags);
+	if (!port_lock_held)
+		spin_unlock_irqrestore(&port->lock, flags);
+	return -EAGAIN;
 }
 
 static void work_fn_tx(struct work_struct *work)
@@ -1491,7 +1494,7 @@ static enum hrtimer_restart rx_timer_fn(struct hrtimer *t)
 	}
 
 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
-		sci_submit_rx(s);
+		sci_submit_rx(s, true);
 
 	/* Direct new serial port interrupts back to CPU */
 	scr = serial_port_in(port, SCSCR);
@@ -1617,7 +1620,7 @@ static void sci_request_dma(struct uart_port *port)
 		s->chan_rx_saved = s->chan_rx = chan;
 
 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
-			sci_submit_rx(s);
+			sci_submit_rx(s, false);
 	}
 }
 
@@ -1666,8 +1669,10 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 			disable_irq_nosync(irq);
 			scr |= SCSCR_RDRQE;
 		} else {
+			if (sci_submit_rx(s, false) < 0)
+				goto handle_pio;
+
 			scr &= ~SCSCR_RIE;
-			sci_submit_rx(s);
 		}
 		serial_port_out(port, SCSCR, scr);
 		/* Clear current interrupt */
@@ -1679,6 +1684,8 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 
 		return IRQ_HANDLED;
 	}
+
+handle_pio:
 #endif
 
 	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
@@ -1693,7 +1700,7 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 	 * of whether the I_IXOFF is set, otherwise, how is the interrupt
 	 * to be disabled?
 	 */
-	sci_receive_chars(ptr);
+	sci_receive_chars(port);
 
 	return IRQ_HANDLED;
 }
@@ -1749,7 +1756,7 @@ static irqreturn_t sci_er_interrupt(int irq, void *ptr)
 	} else {
 		sci_handle_fifo_overrun(port);
 		if (!s->chan_rx)
-			sci_receive_chars(ptr);
+			sci_receive_chars(port);
 	}
 
 	sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
diff --git a/drivers/tty/serial/suncore.c b/drivers/tty/serial/suncore.c
index 990376576970..2491551c293e 100644
--- a/drivers/tty/serial/suncore.c
+++ b/drivers/tty/serial/suncore.c
@@ -89,14 +89,14 @@ void sunserial_console_termios(struct console *con, struct device_node *uart_dp)
 	int baud, bits, stop, cflag;
 	char parity;
 
-	if (!strcmp(uart_dp->name, "rsc") ||
-	    !strcmp(uart_dp->name, "rsc-console") ||
-	    !strcmp(uart_dp->name, "rsc-control")) {
+	if (of_node_name_eq(uart_dp, "rsc") ||
+	    of_node_name_eq(uart_dp, "rsc-console") ||
+	    of_node_name_eq(uart_dp, "rsc-control")) {
 		mode = of_get_property(uart_dp,
 				       "ssp-console-modes", NULL);
 		if (!mode)
 			mode = "115200,8,n,1,-";
-	} else if (!strcmp(uart_dp->name, "lom-console")) {
+	} else if (of_node_name_eq(uart_dp, "lom-console")) {
 		mode = "9600,8,n,1,-";
 	} else {
 		struct device_node *dp;
diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 3e77475668c0..4db6aaa330b2 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -1503,8 +1503,8 @@ static int su_probe(struct platform_device *op)
 	up->port.ops = &sunsu_pops;
 
 	ignore_line = false;
-	if (!strcmp(dp->name, "rsc-console") ||
-	    !strcmp(dp->name, "lom-console"))
+	if (of_node_name_eq(dp, "rsc-console") ||
+	    of_node_name_eq(dp, "lom-console"))
 		ignore_line = true;
 
 	sunserial_console_match(SUNSU_CONSOLE(), dp,
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index f0344adc86db..b8b912b5a8b9 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -22,6 +22,7 @@
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
 #include <linux/clk.h>
+#include <linux/pm_runtime.h>
 
 #define ULITE_NAME		"ttyUL"
 #define ULITE_MAJOR		204
@@ -54,6 +55,7 @@
 #define ULITE_CONTROL_RST_TX	0x01
 #define ULITE_CONTROL_RST_RX	0x02
 #define ULITE_CONTROL_IE	0x10
+#define UART_AUTOSUSPEND_TIMEOUT	3000
 
 /* Static pointer to console port */
 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
@@ -63,6 +65,7 @@ static struct uart_port *console_port;
 struct uartlite_data {
 	const struct uartlite_reg_ops *reg_ops;
 	struct clk *clk;
+	struct uart_driver *ulite_uart_driver;
 };
 
 struct uartlite_reg_ops {
@@ -390,12 +393,12 @@ static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
 static void ulite_pm(struct uart_port *port, unsigned int state,
 		     unsigned int oldstate)
 {
-	struct uartlite_data *pdata = port->private_data;
-
-	if (!state)
-		clk_enable(pdata->clk);
-	else
-		clk_disable(pdata->clk);
+	if (!state) {
+		pm_runtime_get_sync(port->dev);
+	} else {
+		pm_runtime_mark_last_busy(port->dev);
+		pm_runtime_put_autosuspend(port->dev);
+	}
 }
 
 #ifdef CONFIG_CONSOLE_POLL
@@ -694,7 +697,9 @@ static int ulite_release(struct device *dev)
 	int rc = 0;
 
 	if (port) {
-		rc = uart_remove_one_port(&ulite_uart_driver, port);
+		struct uartlite_data *pdata = port->private_data;
+
+		rc = uart_remove_one_port(pdata->ulite_uart_driver, port);
 		dev_set_drvdata(dev, NULL);
 		port->mapbase = 0;
 	}
@@ -712,8 +717,11 @@ static int __maybe_unused ulite_suspend(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 
-	if (port)
-		uart_suspend_port(&ulite_uart_driver, port);
+	if (port) {
+		struct uartlite_data *pdata = port->private_data;
+
+		uart_suspend_port(pdata->ulite_uart_driver, port);
+	}
 
 	return 0;
 }
@@ -728,17 +736,41 @@ static int __maybe_unused ulite_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 
-	if (port)
-		uart_resume_port(&ulite_uart_driver, port);
+	if (port) {
+		struct uartlite_data *pdata = port->private_data;
+
+		uart_resume_port(pdata->ulite_uart_driver, port);
+	}
 
 	return 0;
 }
 
+static int __maybe_unused ulite_runtime_suspend(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct uartlite_data *pdata = port->private_data;
+
+	clk_disable(pdata->clk);
+	return 0;
+};
+
+static int __maybe_unused ulite_runtime_resume(struct device *dev)
+{
+	struct uart_port *port = dev_get_drvdata(dev);
+	struct uartlite_data *pdata = port->private_data;
+
+	clk_enable(pdata->clk);
+	return 0;
+}
 /* ---------------------------------------------------------------------
  * Platform bus binding
  */
 
-static SIMPLE_DEV_PM_OPS(ulite_pm_ops, ulite_suspend, ulite_resume);
+static const struct dev_pm_ops ulite_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume)
+	SET_RUNTIME_PM_OPS(ulite_runtime_suspend,
+			   ulite_runtime_resume, NULL)
+};
 
 #if defined(CONFIG_OF)
 /* Match table for of_platform binding */
@@ -763,6 +795,22 @@ static int ulite_probe(struct platform_device *pdev)
 	if (prop)
 		id = be32_to_cpup(prop);
 #endif
+	if (id < 0) {
+		/* Look for a serialN alias */
+		id = of_alias_get_id(pdev->dev.of_node, "serial");
+		if (id < 0)
+			id = 0;
+	}
+
+	if (!ulite_uart_driver.state) {
+		dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n");
+		ret = uart_register_driver(&ulite_uart_driver);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Failed to register driver\n");
+			return ret;
+		}
+	}
+
 	pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data),
 			     GFP_KERNEL);
 	if (!pdata)
@@ -788,24 +836,22 @@ static int ulite_probe(struct platform_device *pdev)
 		pdata->clk = NULL;
 	}
 
+	pdata->ulite_uart_driver = &ulite_uart_driver;
 	ret = clk_prepare_enable(pdata->clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to prepare clock\n");
 		return ret;
 	}
 
-	if (!ulite_uart_driver.state) {
-		dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n");
-		ret = uart_register_driver(&ulite_uart_driver);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "Failed to register driver\n");
-			return ret;
-		}
-	}
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
 
 	ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata);
 
-	clk_disable(pdata->clk);
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
 
 	return ret;
 }
@@ -814,9 +860,14 @@ static int ulite_remove(struct platform_device *pdev)
 {
 	struct uart_port *port = dev_get_drvdata(&pdev->dev);
 	struct uartlite_data *pdata = port->private_data;
+	int rc;
 
-	clk_disable_unprepare(pdata->clk);
-	return ulite_release(&pdev->dev);
+	clk_unprepare(pdata->clk);
+	rc = ulite_release(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	return rc;
 }
 
 /* work with hotplug and coldplug */
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 57c66d2c3471..094f2958cb2b 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -123,7 +123,7 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
 #define CDNS_UART_IXR_RXTRIG	0x00000001 /* RX FIFO trigger interrupt */
 #define CDNS_UART_IXR_RXFULL	0x00000004 /* RX FIFO full interrupt. */
 #define CDNS_UART_IXR_RXEMPTY	0x00000002 /* RX FIFO empty interrupt. */
-#define CDNS_UART_IXR_MASK	0x00001FFF /* Valid bit mask */
+#define CDNS_UART_IXR_RXMASK	0x000021e7 /* Valid RX bit mask */
 
 	/*
 	 * Do not enable parity error interrupt for the following
@@ -364,7 +364,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
 		cdns_uart_handle_tx(dev_id);
 		isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
 	}
-	if (isrstatus & CDNS_UART_IXR_MASK)
+	if (isrstatus & CDNS_UART_IXR_RXMASK)
 		cdns_uart_handle_rx(dev_id, isrstatus);
 
 	spin_unlock(&port->lock);
@@ -1255,7 +1255,7 @@ static int cdns_uart_suspend(struct device *device)
 
 	may_wake = device_may_wakeup(device);
 
-	if (console_suspend_enabled && may_wake) {
+	if (console_suspend_enabled && uart_console(port) && may_wake) {
 		unsigned long flags = 0;
 
 		spin_lock_irqsave(&port->lock, flags);
@@ -1293,7 +1293,7 @@ static int cdns_uart_resume(struct device *device)
 
 	may_wake = device_may_wakeup(device);
 
-	if (console_suspend_enabled && !may_wake) {
+	if (console_suspend_enabled && uart_console(port) && !may_wake) {
 		clk_enable(cdns_uart->pclk);
 		clk_enable(cdns_uart->uartclk);
 
@@ -1508,8 +1508,10 @@ static int cdns_uart_probe(struct platform_device *pdev)
 #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
 	cdns_uart_console = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_console),
 					 GFP_KERNEL);
-	if (!cdns_uart_console)
-		return -ENOMEM;
+	if (!cdns_uart_console) {
+		rc = -ENOMEM;
+		goto err_out_id;
+	}
 
 	strncpy(cdns_uart_console->name, CDNS_UART_TTY_NAME,
 		sizeof(cdns_uart_console->name));
@@ -1624,6 +1626,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
+	device_init_wakeup(port->dev, true);
 
 #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
 	/*
@@ -1702,6 +1705,7 @@ static int cdns_uart_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	device_init_wakeup(&pdev->dev, false);
 
 #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
 	if (console_port == port)
@@ -1719,6 +1723,7 @@ static struct platform_driver cdns_uart_platform_driver = {
 		.name = CDNS_UART_NAME,
 		.of_match_table = cdns_uart_of_match,
 		.pm = &cdns_uart_dev_pm_ops,
+		.suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_XILINX_PS_UART),
 		},
 };
 
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index ad1ee5d01b53..1f03078ec352 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -134,17 +134,10 @@ static struct sysrq_key_op sysrq_unraw_op = {
 
 static void sysrq_handle_crash(int key)
 {
-	char *killer = NULL;
-
-	/* we need to release the RCU read lock here,
-	 * otherwise we get an annoying
-	 * 'BUG: sleeping function called from invalid context'
-	 * complaint from the kernel before the panic.
-	 */
+	/* release the RCU read lock before crashing */
 	rcu_read_unlock();
-	panic_on_oops = 1;	/* force panic */
-	wmb();
-	*killer = 1;
+
+	panic("sysrq triggered crash\n");
 }
 static struct sysrq_key_op sysrq_crash_op = {
 	.handler	= sysrq_handle_crash,
@@ -660,8 +653,7 @@ static void sysrq_do_reset(struct timer_list *t)
 
 	state->reset_requested = true;
 
-	ksys_sync();
-	kernel_restart(NULL);
+	orderly_reboot();
 }
 
 static void sysrq_handle_reset_request(struct sysrq_state *state)
@@ -736,6 +728,8 @@ static void sysrq_of_get_keyreset_config(void)
 
 	/* Get reset timeout if any. */
 	of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms);
+
+	of_node_put(np);
 }
 #else
 static void sysrq_of_get_keyreset_config(void)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 687250ec8032..bfe9ad85b362 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1268,14 +1268,16 @@ static int tty_reopen(struct tty_struct *tty)
 	if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
 		return -EBUSY;
 
-	tty->count++;
+	retval = tty_ldisc_lock(tty, 5 * HZ);
+	if (retval)
+		return retval;
 
-	if (tty->ldisc)
-		return 0;
+	if (!tty->ldisc)
+		retval = tty_ldisc_reinit(tty, tty->termios.c_line);
+	tty_ldisc_unlock(tty);
 
-	retval = tty_ldisc_reinit(tty, tty->termios.c_line);
-	if (retval)
-		tty->count--;
+	if (retval == 0)
+		tty->count++;
 
 	return retval;
 }
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index fc4c97cae01e..45eda69b150c 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -327,6 +327,11 @@ int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
 {
 	int ret;
 
+	/* Kindly asking blocked readers to release the read side */
+	set_bit(TTY_LDISC_CHANGING, &tty->flags);
+	wake_up_interruptible_all(&tty->read_wait);
+	wake_up_interruptible_all(&tty->write_wait);
+
 	ret = __tty_ldisc_lock(tty, timeout);
 	if (!ret)
 		return -EBUSY;
@@ -337,6 +342,8 @@ int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout)
 void tty_ldisc_unlock(struct tty_struct *tty)
 {
 	clear_bit(TTY_LDISC_HALTED, &tty->flags);
+	/* Can be cleared here - ldisc_unlock will wake up writers firstly */
+	clear_bit(TTY_LDISC_CHANGING, &tty->flags);
 	__tty_ldisc_unlock(tty);
 }
 
@@ -471,6 +478,7 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
 
 static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
 {
+	lockdep_assert_held_exclusive(&tty->ldisc_sem);
 	WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));
 	clear_bit(TTY_LDISC_OPEN, &tty->flags);
 	if (ld->ops->close)
@@ -492,6 +500,7 @@ static int tty_ldisc_failto(struct tty_struct *tty, int ld)
 	struct tty_ldisc *disc = tty_ldisc_get(tty, ld);
 	int r;
 
+	lockdep_assert_held_exclusive(&tty->ldisc_sem);
 	if (IS_ERR(disc))
 		return PTR_ERR(disc);
 	tty->ldisc = disc;
@@ -615,6 +624,7 @@ EXPORT_SYMBOL_GPL(tty_set_ldisc);
  */
 static void tty_ldisc_kill(struct tty_struct *tty)
 {
+	lockdep_assert_held_exclusive(&tty->ldisc_sem);
 	if (!tty->ldisc)
 		return;
 	/*
@@ -662,6 +672,7 @@ int tty_ldisc_reinit(struct tty_struct *tty, int disc)
 	struct tty_ldisc *ld;
 	int retval;
 
+	lockdep_assert_held_exclusive(&tty->ldisc_sem);
 	ld = tty_ldisc_get(tty, disc);
 	if (IS_ERR(ld)) {
 		BUG_ON(disc == N_TTY);
@@ -760,6 +771,10 @@ int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
 		return retval;
 
 	if (o_tty) {
+		/*
+		 * Called without o_tty->ldisc_sem held, as o_tty has been
+		 * just allocated and no one has a reference to it.
+		 */
 		retval = tty_ldisc_open(o_tty, o_tty->ldisc);
 		if (retval) {
 			tty_ldisc_close(tty, tty->ldisc);
@@ -825,6 +840,7 @@ int tty_ldisc_init(struct tty_struct *tty)
  */
 void tty_ldisc_deinit(struct tty_struct *tty)
 {
+	/* no ldisc_sem, tty is being destroyed */
 	if (tty->ldisc)
 		tty_ldisc_put(tty->ldisc);
 	tty->ldisc = NULL;
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index 0c98d88f795a..717292c1c0df 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -34,29 +34,6 @@
 #include <linux/sched/task.h>
 
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __acq(l, s, t, r, c, n, i)		\
-				lock_acquire(&(l)->dep_map, s, t, r, c, n, i)
-# define __rel(l, n, i)				\
-				lock_release(&(l)->dep_map, n, i)
-#define lockdep_acquire(l, s, t, i)		__acq(l, s, t, 0, 1, NULL, i)
-#define lockdep_acquire_nest(l, s, t, n, i)	__acq(l, s, t, 0, 1, n, i)
-#define lockdep_acquire_read(l, s, t, i)	__acq(l, s, t, 1, 1, NULL, i)
-#define lockdep_release(l, n, i)		__rel(l, n, i)
-#else
-# define lockdep_acquire(l, s, t, i)		do { } while (0)
-# define lockdep_acquire_nest(l, s, t, n, i)	do { } while (0)
-# define lockdep_acquire_read(l, s, t, i)	do { } while (0)
-# define lockdep_release(l, n, i)		do { } while (0)
-#endif
-
-#ifdef CONFIG_LOCK_STAT
-# define lock_stat(_lock, stat)		lock_##stat(&(_lock)->dep_map, _RET_IP_)
-#else
-# define lock_stat(_lock, stat)		do { } while (0)
-#endif
-
-
 #if BITS_PER_LONG == 64
 # define LDSEM_ACTIVE_MASK	0xffffffffL
 #else
@@ -235,6 +212,7 @@ down_read_failed(struct ld_semaphore *sem, long count, long timeout)
 		raw_spin_lock_irq(&sem->wait_lock);
 		if (waiter.task) {
 			atomic_long_add_return(-LDSEM_WAIT_BIAS, &sem->count);
+			sem->wait_readers--;
 			list_del(&waiter.list);
 			raw_spin_unlock_irq(&sem->wait_lock);
 			put_task_struct(waiter.task);
@@ -293,6 +271,16 @@ down_write_failed(struct ld_semaphore *sem, long count, long timeout)
 	if (!locked)
 		atomic_long_add_return(-LDSEM_WAIT_BIAS, &sem->count);
 	list_del(&waiter.list);
+
+	/*
+	 * In case of timeout, wake up every reader who gave the right of way
+	 * to writer. Prevent separation readers into two groups:
+	 * one that helds semaphore and another that sleeps.
+	 * (in case of no contention with a writer)
+	 */
+	if (!locked && list_empty(&sem->write_wait))
+		__ldsem_wake_readers(sem);
+
 	raw_spin_unlock_irq(&sem->wait_lock);
 
 	__set_current_state(TASK_RUNNING);
@@ -310,17 +298,17 @@ static int __ldsem_down_read_nested(struct ld_semaphore *sem,
 {
 	long count;
 
-	lockdep_acquire_read(sem, subclass, 0, _RET_IP_);
+	rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_);
 
 	count = atomic_long_add_return(LDSEM_READ_BIAS, &sem->count);
 	if (count <= 0) {
-		lock_stat(sem, contended);
+		lock_contended(&sem->dep_map, _RET_IP_);
 		if (!down_read_failed(sem, count, timeout)) {
-			lockdep_release(sem, 1, _RET_IP_);
+			rwsem_release(&sem->dep_map, 1, _RET_IP_);
 			return 0;
 		}
 	}
-	lock_stat(sem, acquired);
+	lock_acquired(&sem->dep_map, _RET_IP_);
 	return 1;
 }
 
@@ -329,17 +317,17 @@ static int __ldsem_down_write_nested(struct ld_semaphore *sem,
 {
 	long count;
 
-	lockdep_acquire(sem, subclass, 0, _RET_IP_);
+	rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_);
 
 	count = atomic_long_add_return(LDSEM_WRITE_BIAS, &sem->count);
 	if ((count & LDSEM_ACTIVE_MASK) != LDSEM_ACTIVE_BIAS) {
-		lock_stat(sem, contended);
+		lock_contended(&sem->dep_map, _RET_IP_);
 		if (!down_write_failed(sem, count, timeout)) {
-			lockdep_release(sem, 1, _RET_IP_);
+			rwsem_release(&sem->dep_map, 1, _RET_IP_);
 			return 0;
 		}
 	}
-	lock_stat(sem, acquired);
+	lock_acquired(&sem->dep_map, _RET_IP_);
 	return 1;
 }
 
@@ -362,8 +350,8 @@ int ldsem_down_read_trylock(struct ld_semaphore *sem)
 
 	while (count >= 0) {
 		if (atomic_long_try_cmpxchg(&sem->count, &count, count + LDSEM_READ_BIAS)) {
-			lockdep_acquire_read(sem, 0, 1, _RET_IP_);
-			lock_stat(sem, acquired);
+			rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
+			lock_acquired(&sem->dep_map, _RET_IP_);
 			return 1;
 		}
 	}
@@ -388,8 +376,8 @@ int ldsem_down_write_trylock(struct ld_semaphore *sem)
 
 	while ((count & LDSEM_ACTIVE_MASK) == 0) {
 		if (atomic_long_try_cmpxchg(&sem->count, &count, count + LDSEM_WRITE_BIAS)) {
-			lockdep_acquire(sem, 0, 1, _RET_IP_);
-			lock_stat(sem, acquired);
+			rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
+			lock_acquired(&sem->dep_map, _RET_IP_);
 			return 1;
 		}
 	}
@@ -403,7 +391,7 @@ void ldsem_up_read(struct ld_semaphore *sem)
 {
 	long count;
 
-	lockdep_release(sem, 1, _RET_IP_);
+	rwsem_release(&sem->dep_map, 1, _RET_IP_);
 
 	count = atomic_long_add_return(-LDSEM_READ_BIAS, &sem->count);
 	if (count < 0 && (count & LDSEM_ACTIVE_MASK) == 0)
@@ -417,7 +405,7 @@ void ldsem_up_write(struct ld_semaphore *sem)
 {
 	long count;
 
-	lockdep_release(sem, 1, _RET_IP_);
+	rwsem_release(&sem->dep_map, 1, _RET_IP_);
 
 	count = atomic_long_add_return(-LDSEM_WRITE_BIAS, &sem->count);
 	if (count < 0)
author	Linus Torvalds <torvalds@linux-foundation.org>	2018-12-28 20:33:54 -0800
committer	Linus Torvalds <torvalds@linux-foundation.org>	2018-12-28 20:33:54 -0800
commit	117eda8f71ff545cfdec8fe8073adbd173a1ceff (patch)
tree	7a6fe1729d34581c563b5f7a883f049ee272f1e3 /drivers/tty
parent	c0ea81b4d37837409d0dfd2036098a7babb312ed (diff)
parent	598134ffcab5bfb1d342458732394487063e1b9e (diff)