From a360fae67bc173942f620d44d1b23cfb5ccaaf96 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Tue, 1 Jun 2010 22:52:50 +0200 Subject: synclink: reworking locking a bit Use the port mutex and port lock to fix the various races. The locking still isn't totally consistent but its better than before. Wants switching to the port helpers. Signed-off-by: Alan Cox Cc: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- drivers/char/synclink_gt.c | 12 +++++++++++- drivers/char/synclinkmp.c | 9 ++++++++- 2 files changed, 19 insertions(+), 2 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c index 3c7ac6a..5a602eb 100644 --- a/drivers/char/synclink_gt.c +++ b/drivers/char/synclink_gt.c @@ -675,12 +675,14 @@ static int open(struct tty_struct *tty, struct file *filp) goto cleanup; } + mutex_lock(&info->port.mutex); info->port.tty->low_latency = (info->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0; spin_lock_irqsave(&info->netlock, flags); if (info->netcount) { retval = -EBUSY; spin_unlock_irqrestore(&info->netlock, flags); + mutex_unlock(&info->port.mutex); goto cleanup; } info->port.count++; @@ -692,7 +694,7 @@ static int open(struct tty_struct *tty, struct file *filp) if (retval < 0) goto cleanup; } - + mutex_unlock(&info->port.mutex); retval = block_til_ready(tty, filp, info); if (retval) { DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval)); @@ -724,12 +726,14 @@ static void close(struct tty_struct *tty, struct file *filp) if (tty_port_close_start(&info->port, tty, filp) == 0) goto cleanup; + mutex_lock(&info->port.mutex); if (info->port.flags & ASYNC_INITIALIZED) wait_until_sent(tty, info->timeout); flush_buffer(tty); tty_ldisc_flush(tty); shutdown(info); + mutex_unlock(&info->port.mutex); tty_port_close_end(&info->port, tty); info->port.tty = NULL; @@ -740,17 +744,23 @@ cleanup: static void hangup(struct tty_struct *tty) { struct slgt_info *info = tty->driver_data; + unsigned long flags; if (sanity_check(info, tty->name, "hangup")) return; DBGINFO(("%s hangup\n", info->device_name)); flush_buffer(tty); + + mutex_lock(&info->port.mutex); shutdown(info); + spin_lock_irqsave(&info->port.lock, flags); info->port.count = 0; info->port.flags &= ~ASYNC_NORMAL_ACTIVE; info->port.tty = NULL; + spin_unlock_irqrestore(&info->port.lock, flags); + mutex_unlock(&info->port.mutex); wake_up_interruptible(&info->port.open_wait); } diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c index 8da976b..ac447c7 100644 --- a/drivers/char/synclinkmp.c +++ b/drivers/char/synclinkmp.c @@ -812,13 +812,15 @@ static void close(struct tty_struct *tty, struct file *filp) if (tty_port_close_start(&info->port, tty, filp) == 0) goto cleanup; - + + mutex_lock(&info->port.mutex); if (info->port.flags & ASYNC_INITIALIZED) wait_until_sent(tty, info->timeout); flush_buffer(tty); tty_ldisc_flush(tty); shutdown(info); + mutex_unlock(&info->port.mutex); tty_port_close_end(&info->port, tty); info->port.tty = NULL; @@ -834,6 +836,7 @@ cleanup: static void hangup(struct tty_struct *tty) { SLMP_INFO *info = tty->driver_data; + unsigned long flags; if (debug_level >= DEBUG_LEVEL_INFO) printk("%s(%d):%s hangup()\n", @@ -842,12 +845,16 @@ static void hangup(struct tty_struct *tty) if (sanity_check(info, tty->name, "hangup")) return; + mutex_lock(&info->port.mutex); flush_buffer(tty); shutdown(info); + spin_lock_irqsave(&info->port.lock, flags); info->port.count = 0; info->port.flags &= ~ASYNC_NORMAL_ACTIVE; info->port.tty = NULL; + spin_unlock_irqrestore(&info->port.lock, flags); + mutex_unlock(&info->port.mutex); wake_up_interruptible(&info->port.open_wait); } -- cgit v1.1