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/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);
}