Merge tag 'tty-6.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 6.9-rc5 that
  resolve a bunch of reported problems. Included in here are:

   - MAINTAINERS and .mailmap update for Richard Genoud

   - serial core regression fixes from 6.9-rc1 changes

   - pci id cleanups

   - serial core crash fix

   - stm32 driver fixes

   - 8250 driver fixes

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-6.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: stm32: Reset .throttled state in .startup()
  serial: stm32: Return IRQ_NONE in the ISR if no handling happend
  serial: core: Fix missing shutdown and startup for serial base port
  serial: core: Clearing the circular buffer before NULLifying it
  MAINTAINERS: mailmap: update Richard Genoud's email address
  serial/pmac_zilog: Remove flawed mitigation for rx irq flood
  serial: 8250_pci: Remove redundant PCI IDs
  serial: core: Fix regression when runtime PM is not enabled
  serial: mxs-auart: add spinlock around changing cts state
  serial: 8250_dw: Revert: Do not reclock if already at correct rate
  serial: 8250_lpc18xx: disable clks on error in probe()

12 files changed, 81 insertions, 34 deletions

diff --git a/.mailmap b/.mailmap
index 625b496bf5f4..f877262b0be9 100644
--- a/.mailmap
+++ b/.mailmap
@@ -525,6 +525,7 @@ Rémi Denis-Courmont <rdenis@simphalempin.com>
 Ricardo Ribalda <ribalda@kernel.org> <ricardo@ribalda.com>
 Ricardo Ribalda <ribalda@kernel.org> Ricardo Ribalda Delgado <ribalda@kernel.org>
 Ricardo Ribalda <ribalda@kernel.org> <ricardo.ribalda@gmail.com>
+Richard Genoud <richard.genoud@bootlin.com> <richard.genoud@gmail.com>
 Richard Leitner <richard.leitner@linux.dev> <dev@g0hl1n.net>
 Richard Leitner <richard.leitner@linux.dev> <me@g0hl1n.net>
 Richard Leitner <richard.leitner@linux.dev> <richard.leitner@skidata.com>
diff --git a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
index 65cb2e5c5eee..eb2992a447d7 100644
--- a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
+++ b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
@@ -8,7 +8,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 title: Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
 
 maintainers:
-  - Richard Genoud <richard.genoud@gmail.com>
+  - Richard Genoud <richard.genoud@bootlin.com>
 
 properties:
   compatible:
diff --git a/MAINTAINERS b/MAINTAINERS
index 4b6db2054713..ebf03f5f0619 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14356,7 +14356,7 @@ F:	drivers/dma/at_xdmac.c
 F:	include/dt-bindings/dma/at91.h
 
 MICROCHIP AT91 SERIAL DRIVER
-M:	Richard Genoud <richard.genoud@gmail.com>
+M:	Richard Genoud <richard.genoud@bootlin.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
 F:	drivers/tty/serial/atmel_serial.c
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a3acbf0f5da1..1300c92b8702 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -356,9 +356,9 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 	long rate;
 	int ret;
 
+	clk_disable_unprepare(d->clk);
 	rate = clk_round_rate(d->clk, newrate);
-	if (rate > 0 && p->uartclk != rate) {
-		clk_disable_unprepare(d->clk);
+	if (rate > 0) {
 		/*
 		 * Note that any clock-notifer worker will block in
 		 * serial8250_update_uartclk() until we are done.
@@ -366,8 +366,8 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 		ret = clk_set_rate(d->clk, newrate);
 		if (!ret)
 			p->uartclk = rate;
-		clk_prepare_enable(d->clk);
 	}
+	clk_prepare_enable(d->clk);
 
 	dw8250_do_set_termios(p, termios, old);
 }
diff --git a/drivers/tty/serial/8250/8250_lpc18xx.c b/drivers/tty/serial/8250/8250_lpc18xx.c
index 7984ee05af1d..47e1a056a60c 100644
--- a/drivers/tty/serial/8250/8250_lpc18xx.c
+++ b/drivers/tty/serial/8250/8250_lpc18xx.c
@@ -151,7 +151,7 @@ static int lpc18xx_serial_probe(struct platform_device *pdev)
 
 	ret = uart_read_port_properties(&uart.port);
 	if (ret)
-		return ret;
+		goto dis_uart_clk;
 
 	uart.port.iotype = UPIO_MEM32;
 	uart.port.regshift = 2;
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 0d35c77fad9e..e2e4f99f9d34 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -5010,12 +5010,6 @@ static const struct pci_device_id serial_pci_tbl[] = {
 	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATRO_B,
 		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 		pbn_b0_bt_2_115200 },
-	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATTRO_A,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_b0_bt_2_115200 },
-	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_QUATTRO_B,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_b0_bt_2_115200 },
 	{	PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_OCTO_A,
 		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 		pbn_b0_bt_4_460800 },
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 4749331fe618..1e8853eae504 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -1086,11 +1086,13 @@ static void mxs_auart_set_ldisc(struct uart_port *port,
 
 static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 {
-	u32 istat;
+	u32 istat, stat;
 	struct mxs_auart_port *s = context;
 	u32 mctrl_temp = s->mctrl_prev;
-	u32 stat = mxs_read(s, REG_STAT);
 
+	uart_port_lock(&s->port);
+
+	stat = mxs_read(s, REG_STAT);
 	istat = mxs_read(s, REG_INTR);
 
 	/* ack irq */
@@ -1126,6 +1128,8 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 		istat &= ~AUART_INTR_TXIS;
 	}
 
+	uart_port_unlock(&s->port);
+
 	return IRQ_HANDLED;
 }
 
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 05d97e89511e..92195f984de1 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -210,7 +210,6 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap)
 {
 	struct tty_port *port;
 	unsigned char ch, r1, drop, flag;
-	int loops = 0;
 
 	/* Sanity check, make sure the old bug is no longer happening */
 	if (uap->port.state == NULL) {
@@ -291,25 +290,12 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap)
 		if (r1 & Rx_OVR)
 			tty_insert_flip_char(port, 0, TTY_OVERRUN);
 	next_char:
-		/* We can get stuck in an infinite loop getting char 0 when the
-		 * line is in a wrong HW state, we break that here.
-		 * When that happens, I disable the receive side of the driver.
-		 * Note that what I've been experiencing is a real irq loop where
-		 * I'm getting flooded regardless of the actual port speed.
-		 * Something strange is going on with the HW
-		 */
-		if ((++loops) > 1000)
-			goto flood;
 		ch = read_zsreg(uap, R0);
 		if (!(ch & Rx_CH_AV))
 			break;
 	}
 
 	return true;
- flood:
-	pmz_interrupt_control(uap, 0);
-	pmz_error("pmz: rx irq flood !\n");
-	return true;
 }
 
 static void pmz_status_handle(struct uart_pmac_port *uap)
diff --git a/drivers/tty/serial/serial_base.h b/drivers/tty/serial/serial_base.h
index c74c548f0db6..b6c38d2edfd4 100644
--- a/drivers/tty/serial/serial_base.h
+++ b/drivers/tty/serial/serial_base.h
@@ -22,6 +22,7 @@ struct serial_ctrl_device {
 struct serial_port_device {
 	struct device dev;
 	struct uart_port *port;
+	unsigned int tx_enabled:1;
 };
 
 int serial_base_ctrl_init(void);
@@ -30,6 +31,9 @@ void serial_base_ctrl_exit(void);
 int serial_base_port_init(void);
 void serial_base_port_exit(void);
 
+void serial_base_port_startup(struct uart_port *port);
+void serial_base_port_shutdown(struct uart_port *port);
+
 int serial_base_driver_register(struct device_driver *driver);
 void serial_base_driver_unregister(struct device_driver *driver);
 
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index ff85ebd3a007..c476d884356d 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -156,7 +156,7 @@ static void __uart_start(struct uart_state *state)
 	 * enabled, serial_port_runtime_resume() calls start_tx() again
 	 * after enabling the device.
 	 */
-	if (pm_runtime_active(&port_dev->dev))
+	if (!pm_runtime_enabled(port->dev) || pm_runtime_active(&port_dev->dev))
 		port->ops->start_tx(port);
 	pm_runtime_mark_last_busy(&port_dev->dev);
 	pm_runtime_put_autosuspend(&port_dev->dev);
@@ -323,16 +323,26 @@ static int uart_startup(struct tty_struct *tty, struct uart_state *state,
 			bool init_hw)
 {
 	struct tty_port *port = &state->port;
+	struct uart_port *uport;
 	int retval;
 
 	if (tty_port_initialized(port))
-		return 0;
+		goto out_base_port_startup;
 
 	retval = uart_port_startup(tty, state, init_hw);
-	if (retval)
+	if (retval) {
 		set_bit(TTY_IO_ERROR, &tty->flags);
+		return retval;
+	}
 
-	return retval;
+out_base_port_startup:
+	uport = uart_port_check(state);
+	if (!uport)
+		return -EIO;
+
+	serial_base_port_startup(uport);
+
+	return 0;
 }
 
 /*
@@ -355,6 +365,9 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 	if (tty)
 		set_bit(TTY_IO_ERROR, &tty->flags);
 
+	if (uport)
+		serial_base_port_shutdown(uport);
+
 	if (tty_port_initialized(port)) {
 		tty_port_set_initialized(port, false);
 
@@ -1775,6 +1788,7 @@ static void uart_tty_port_shutdown(struct tty_port *port)
 	uport->ops->stop_rx(uport);
 	uart_port_unlock_irq(uport);
 
+	serial_base_port_shutdown(uport);
 	uart_port_shutdown(port);
 
 	/*
@@ -1788,6 +1802,7 @@ static void uart_tty_port_shutdown(struct tty_port *port)
 	 * Free the transmit buffer.
 	 */
 	uart_port_lock_irq(uport);
+	uart_circ_clear(&state->xmit);
 	buf = state->xmit.buf;
 	state->xmit.buf = NULL;
 	uart_port_unlock_irq(uport);
diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c
index 22b9eeb23e68..7e3a1c7b097c 100644
--- a/drivers/tty/serial/serial_port.c
+++ b/drivers/tty/serial/serial_port.c
@@ -39,8 +39,12 @@ static int serial_port_runtime_resume(struct device *dev)
 
 	/* Flush any pending TX for the port */
 	uart_port_lock_irqsave(port, &flags);
+	if (!port_dev->tx_enabled)
+		goto unlock;
 	if (__serial_port_busy(port))
 		port->ops->start_tx(port);
+
+unlock:
 	uart_port_unlock_irqrestore(port, flags);
 
 out:
@@ -60,6 +64,11 @@ static int serial_port_runtime_suspend(struct device *dev)
 		return 0;
 
 	uart_port_lock_irqsave(port, &flags);
+	if (!port_dev->tx_enabled) {
+		uart_port_unlock_irqrestore(port, flags);
+		return 0;
+	}
+
 	busy = __serial_port_busy(port);
 	if (busy)
 		port->ops->start_tx(port);
@@ -71,6 +80,31 @@ static int serial_port_runtime_suspend(struct device *dev)
 	return busy ? -EBUSY : 0;
 }
 
+static void serial_base_port_set_tx(struct uart_port *port,
+				    struct serial_port_device *port_dev,
+				    bool enabled)
+{
+	unsigned long flags;
+
+	uart_port_lock_irqsave(port, &flags);
+	port_dev->tx_enabled = enabled;
+	uart_port_unlock_irqrestore(port, flags);
+}
+
+void serial_base_port_startup(struct uart_port *port)
+{
+	struct serial_port_device *port_dev = port->port_dev;
+
+	serial_base_port_set_tx(port, port_dev, true);
+}
+
+void serial_base_port_shutdown(struct uart_port *port)
+{
+	struct serial_port_device *port_dev = port->port_dev;
+
+	serial_base_port_set_tx(port, port_dev, false);
+}
+
 static DEFINE_RUNTIME_DEV_PM_OPS(serial_port_pm,
 				 serial_port_runtime_suspend,
 				 serial_port_runtime_resume, NULL);
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 58d169e5c1db..4fa5a03ebac0 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -861,6 +861,7 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	u32 sr;
 	unsigned int size;
+	irqreturn_t ret = IRQ_NONE;
 
 	sr = readl_relaxed(port->membase + ofs->isr);
 
@@ -869,11 +870,14 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 	    (sr & USART_SR_TC)) {
 		stm32_usart_tc_interrupt_disable(port);
 		stm32_usart_rs485_rts_disable(port);
+		ret = IRQ_HANDLED;
 	}
 
-	if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG)
+	if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG) {
 		writel_relaxed(USART_ICR_RTOCF,
 			       port->membase + ofs->icr);
+		ret = IRQ_HANDLED;
+	}
 
 	if ((sr & USART_SR_WUF) && ofs->icr != UNDEF_REG) {
 		/* Clear wake up flag and disable wake up interrupt */
@@ -882,6 +886,7 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE);
 		if (irqd_is_wakeup_set(irq_get_irq_data(port->irq)))
 			pm_wakeup_event(tport->tty->dev, 0);
+		ret = IRQ_HANDLED;
 	}
 
 	/*
@@ -896,6 +901,7 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 			uart_unlock_and_check_sysrq(port);
 			if (size)
 				tty_flip_buffer_push(tport);
+			ret = IRQ_HANDLED;
 		}
 	}
 
@@ -903,6 +909,7 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 		uart_port_lock(port);
 		stm32_usart_transmit_chars(port);
 		uart_port_unlock(port);
+		ret = IRQ_HANDLED;
 	}
 
 	/* Receiver timeout irq for DMA RX */
@@ -912,9 +919,10 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 		uart_unlock_and_check_sysrq(port);
 		if (size)
 			tty_flip_buffer_push(tport);
+		ret = IRQ_HANDLED;
 	}
 
-	return IRQ_HANDLED;
+	return ret;
 }
 
 static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
@@ -1084,6 +1092,7 @@ static int stm32_usart_startup(struct uart_port *port)
 		val |= USART_CR2_SWAP;
 		writel_relaxed(val, port->membase + ofs->cr2);
 	}
+	stm32_port->throttled = false;
 
 	/* RX FIFO Flush */
 	if (ofs->rqr != UNDEF_REG)