timers: Fix slack calculation for expired timers

commit 3bbb9ec946 (timers: Introduce the concept of timer slack for
legacy timers) does not take the case into account when the timer is
already expired. This broke wireless drivers.

The solution is not to apply slack to already expired timers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
This commit is contained in:
Jeff Chua 2010-05-24 07:16:24 +08:00 committed by Thomas Gleixner
parent bd45b7a385
commit f00e047efd

View File

@ -750,13 +750,14 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
unsigned long expires_limit, mask;
int bit;
expires_limit = expires + timer->slack;
expires_limit = expires;
if (timer->slack < 0) /* auto slack: use 0.4% */
if (timer->slack > -1)
expires_limit = expires + timer->slack;
else if (time_after(expires, jiffies)) /* auto slack: use 0.4% */
expires_limit = expires + (expires - jiffies)/256;
mask = expires ^ expires_limit;
if (mask == 0)
return expires;