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XTENSA: iss/console, fix potential deadlock 

If the timer ticks while we are holding the spinlock, the system
deadlocks. It is due to synchronous del_timer.

So to fix that, use spinlocks that properly disable bottom halves.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2012-03-05 14:52:06 +01:00 committed by Greg Kroah-Hartman
parent 86e7e87463
commit c9ddb1d6e2
1 changed files with 2 additions and 3 deletions
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5
arch/xtensa/platforms/iss/console.c
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@ -91,11 +91,10 @@ static int rs_open(struct tty_struct *tty, struct file * filp)
*/
static void rs_close(struct tty_struct *tty, struct file * filp)
{
spin_lock(&timer_lock);
spin_lock_bh(&timer_lock);
if (tty->count == 1)
/* this will cause a deadlock if the timer ticks right now */
del_timer_sync(&serial_timer);
spin_unlock(&timer_lock);
spin_unlock_bh(&timer_lock);
}