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authorSteve French <sfrench@us.ibm.com>2008-05-06 17:55:32 +0000
committerSteve French <sfrench@us.ibm.com>2008-05-06 17:55:32 +0000
commita815752ac0ffdb910e92958d41d28f4fb28e5296 (patch)
treea3aa16a282354da0debe8e3a3a7ed8aac6e54001 /drivers/serial/serial_core.c
parent5ade9deaaa3e1f7291467d97b238648e43eae15e (diff)
parenta15306365a16380f3bafee9e181ba01231d4acd7 (diff)
Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'drivers/serial/serial_core.c')
-rw-r--r--drivers/serial/serial_core.c54
1 files changed, 37 insertions, 17 deletions
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 977ce820ce30..1e2b9d826f69 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -422,6 +422,7 @@ uart_get_divisor(struct uart_port *port, unsigned int baud)
EXPORT_SYMBOL(uart_get_divisor);
+/* FIXME: Consistent locking policy */
static void
uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
{
@@ -454,27 +455,30 @@ uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
port->ops->set_termios(port, termios, old_termios);
}
-static inline void
+static inline int
__uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
{
unsigned long flags;
+ int ret = 0;
if (!circ->buf)
- return;
+ return 0;
spin_lock_irqsave(&port->lock, flags);
if (uart_circ_chars_free(circ) != 0) {
circ->buf[circ->head] = c;
circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
+ ret = 1;
}
spin_unlock_irqrestore(&port->lock, flags);
+ return ret;
}
-static void uart_put_char(struct tty_struct *tty, unsigned char ch)
+static int uart_put_char(struct tty_struct *tty, unsigned char ch)
{
struct uart_state *state = tty->driver_data;
- __uart_put_char(state->port, &state->info->xmit, ch);
+ return __uart_put_char(state->port, &state->info->xmit, ch);
}
static void uart_flush_chars(struct tty_struct *tty)
@@ -528,15 +532,25 @@ uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
static int uart_write_room(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
+ unsigned long flags;
+ int ret;
- return uart_circ_chars_free(&state->info->xmit);
+ spin_lock_irqsave(&state->port->lock, flags);
+ ret = uart_circ_chars_free(&state->info->xmit);
+ spin_unlock_irqrestore(&state->port->lock, flags);
+ return ret;
}
static int uart_chars_in_buffer(struct tty_struct *tty)
{
struct uart_state *state = tty->driver_data;
+ unsigned long flags;
+ int ret;
- return uart_circ_chars_pending(&state->info->xmit);
+ spin_lock_irqsave(&state->port->lock, flags);
+ ret = uart_circ_chars_pending(&state->info->xmit);
+ spin_unlock_irqrestore(&state->port->lock, flags);
+ return ret;
}
static void uart_flush_buffer(struct tty_struct *tty)
@@ -618,6 +632,11 @@ static int uart_get_info(struct uart_state *state,
struct serial_struct tmp;
memset(&tmp, 0, sizeof(tmp));
+
+ /* Ensure the state we copy is consistent and no hardware changes
+ occur as we go */
+ mutex_lock(&state->mutex);
+
tmp.type = port->type;
tmp.line = port->line;
tmp.port = port->iobase;
@@ -637,6 +656,8 @@ static int uart_get_info(struct uart_state *state,
tmp.iomem_reg_shift = port->regshift;
tmp.iomem_base = (void *)(unsigned long)port->mapbase;
+ mutex_unlock(&state->mutex);
+
if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
return -EFAULT;
return 0;
@@ -914,8 +935,6 @@ static void uart_break_ctl(struct tty_struct *tty, int break_state)
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->port;
- BUG_ON(!kernel_locked());
-
mutex_lock(&state->mutex);
if (port->type != PORT_UNKNOWN)
@@ -1059,7 +1078,7 @@ static int uart_get_count(struct uart_state *state,
}
/*
- * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here.
+ * Called via sys_ioctl. We can use spin_lock_irq() here.
*/
static int
uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
@@ -1069,7 +1088,6 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
void __user *uarg = (void __user *)arg;
int ret = -ENOIOCTLCMD;
- BUG_ON(!kernel_locked());
/*
* These ioctls don't rely on the hardware to be present.
@@ -1140,9 +1158,9 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
break;
}
}
- out_up:
+out_up:
mutex_unlock(&state->mutex);
- out:
+out:
return ret;
}
@@ -1153,7 +1171,6 @@ static void uart_set_termios(struct tty_struct *tty,
unsigned long flags;
unsigned int cflag = tty->termios->c_cflag;
- BUG_ON(!kernel_locked());
/*
* These are the bits that are used to setup various
@@ -1165,8 +1182,9 @@ static void uart_set_termios(struct tty_struct *tty,
if ((cflag ^ old_termios->c_cflag) == 0 &&
tty->termios->c_ospeed == old_termios->c_ospeed &&
tty->termios->c_ispeed == old_termios->c_ispeed &&
- RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
+ RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
return;
+ }
uart_change_speed(state, old_termios);
@@ -1200,7 +1218,6 @@ static void uart_set_termios(struct tty_struct *tty,
}
spin_unlock_irqrestore(&state->port->lock, flags);
}
-
#if 0
/*
* No need to wake up processes in open wait, since they
@@ -1316,11 +1333,11 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
struct uart_port *port = state->port;
unsigned long char_time, expire;
- BUG_ON(!kernel_locked());
-
if (port->type == PORT_UNKNOWN || port->fifosize == 0)
return;
+ lock_kernel();
+
/*
* Set the check interval to be 1/5 of the estimated time to
* send a single character, and make it at least 1. The check
@@ -1366,6 +1383,7 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
break;
}
set_current_state(TASK_RUNNING); /* might not be needed */
+ unlock_kernel();
}
/*
@@ -2079,7 +2097,9 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
int ret;
uart_change_pm(state, 0);
+ spin_lock_irq(&port->lock);
ops->set_mctrl(port, 0);
+ spin_unlock_irq(&port->lock);
ret = ops->startup(port);
if (ret == 0) {
uart_change_speed(state, NULL);