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Revert "rtc: Expire alarms after the time is set." 

This reverts commit 93b2ec0128.

The call to "schedule_work()" in rtc_initialize_alarm() happens too
early, and can cause oopses at bootup

Neil Brown explains why we do it:

  "If you set an alarm in the future, then shutdown and boot again after
   that time, then you will end up with a timer_queue node which is in
   the past.

   When this happens the queue gets stuck.  That entry-in-the-past won't
   get removed until and interrupt happens and an interrupt won't happen
   because the RTC only triggers an interrupt when the alarm is "now".

   So you'll find that e.g.  "hwclock" will always tell you that
   'select' timed out.

   So we force the interrupt work to happen at the start just in case."

and has a patch that convert it to do things in-process rather than with
the worker thread, but right now it's too late to play around with this,
so we just revert the patch that caused problems for now.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Requested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Requested-by: John Stultz <john.stultz@linaro.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2012-01-04 07:57:22 -08:00
parent 157e8bf8b4
commit f423fc627b
1 changed files with 0 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/rtc/interface.c
View File

@ -73,8 +73,6 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
err = -EINVAL;
mutex_unlock(&rtc->ops_lock);
/* A timer might have just expired */
schedule_work(&rtc->irqwork);
return err;
}
EXPORT_SYMBOL_GPL(rtc_set_time);
@ -114,8 +112,6 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
err = -EINVAL;
mutex_unlock(&rtc->ops_lock);
/* A timer might have just expired */
schedule_work(&rtc->irqwork);
return err;
}
@ -400,8 +396,6 @@ int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
}
mutex_unlock(&rtc->ops_lock);
/* maybe that was in the past.*/
schedule_work(&rtc->irqwork);
return err;
}
EXPORT_SYMBOL_GPL(rtc_initialize_alarm);