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 <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 3c7ac6a3ff809e9b2a8275d82e902fa91b1c2666..5a602eb7cd2d9c8a5789f5bae59ad147b1dcd873 100644 (file)
--- 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 8da976bd7314d3a3470329df1756a839fb9d3be3..ac447c7eb572a4f20bbdf51d82f27377fa3cb1e4 100644 (file)
--- 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);
 }