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 3c7ac6a..5a602eb 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -675,12 +675,14 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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);
}