linux-toradex.git/include/linux/alarmtimer.h, branch v4.6-rc6

alarmtimer: Get rid of unused return value

2015-04-22T15:06:52+00:00

We want to get rid of the hrtimer_start() return value and the alarm
timer return value is nowhere used. Remove it.

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Cc: Preeti U Murthy 
Cc: Viresh Kumar 
Cc: Marcelo Tosatti 
Cc: Frederic Weisbecker 
Cc: John Stultz 
Link: http://lkml.kernel.org/r/20150414203503.243910615@linutronix.de
Signed-off-by: Thomas Gleixner

alarmtimer: Add functions for timerfd support

2013-05-29T19:57:34+00:00

Add functions needed for hooking up alarmtimer to timerfd:

* alarm_restart: Similar to hrtimer_restart, restart an alarmtimer after
  the expires time has already been updated (as with alarm_forward).

* alarm_forward_now: Similar to hrtimer_forward_now, move the expires
  time forward to an interval from the current time of the associated clock.

* alarm_start_relative: Start an alarmtimer with an expires time relative to
  the current time of the associated clock.

* alarm_expires_remaining: Similar to hrtimer_expires_remaining, return the
  amount of time remaining until alarm expiry.

Signed-off-by: Todd Poynor 
Signed-off-by: John Stultz

alarmtimer: Remove unused helpers & defines

2012-09-24T16:38:02+00:00

No one is using these alarmtimer state helpers, so yank them.

Cc: Arve Hjønnevåg 
Cc: Colin Cross 
Cc: Thomas Gleixner 
Signed-off-by: John Stultz

alarmtimer: Use hrtimer per-alarm instead of per-base

2012-09-24T16:38:02+00:00

Arve Hjønnevåg reported numerous crashes from the
"BUG_ON(timer->state != HRTIMER_STATE_CALLBACK)" check
in __run_hrtimer after it called alarmtimer_fired.

It ends up the alarmtimer code was not properly handling
possible failures of hrtimer_try_to_cancel, and because
these faulres occur when the underlying base hrtimer is
being run, this limits the ability to properly handle
modifications to any alarmtimers on that base.

Because much of the logic duplicates the hrtimer logic,
it seems that we might as well have a per-alarmtimer
hrtimer, and avoid the extra complextity of trying to
multiplex many alarmtimers off of one hrtimer.

Thus this patch moves the hrtimer to the alarm structure
and simplifies the management logic.

Changelog:
v2:
* Includes a fix for double alarm_start calls found by
  Arve

Cc: Arve Hjønnevåg 
Cc: Colin Cross 
Cc: Thomas Gleixner 
Reported-by: Arve Hjønnevåg 
Tested-by: Arve Hjønnevåg 
Signed-off-by: John Stultz

alarmtimer: Provide accessor to alarmtimer rtc device

2012-04-20T21:56:36+00:00

The Android alarm interface provides a settime call that sets both
the alarmtimer RTC device and CLOCK_REALTIME to the same value.

Since there may be multiple rtc devices, provide a hook to access the
one the alarmtimer infrastructure is using.

CC: Colin Cross 
CC: Thomas Gleixner 
CC: Android Kernel Team 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

alarmtimers: Add try_to_cancel functionality

2011-08-10T21:55:29+00:00

There's a number of edge cases when cancelling a alarm, so
to be sure we accurately do so, introduce try_to_cancel, which
returns proper failure errors if it cannot. Also modify cancel
to spin until the alarm is properly disabled.

CC: Thomas Gleixner 
Signed-off-by: John Stultz

alarmtimers: Add more refined alarm state tracking

2011-08-10T21:55:27+00:00

In order to allow for functionality like try_to_cancel, add
more refined  state tracking (similar to hrtimers).

CC: Thomas Gleixner 
Signed-off-by: John Stultz

alarmtimers: Remove period from alarm structure

2011-08-10T21:55:26+00:00

Now that periodic alarmtimers are managed by the handler function,
remove the period value from the alarm structure and let the handlers
manage the interval on their own.

CC: Thomas Gleixner 
Signed-off-by: John Stultz

alarmtimers: Add alarm_forward functionality

2011-08-10T21:55:23+00:00

In order to avoid wasting time expiring and re-adding very high freq
periodic alarmtimers, introduce alarm_forward() which is similar to
hrtimer_forward and moves the timer to the next future expiration time
and returns the number of overruns.

CC: Thomas Gleixner 
Signed-off-by: John Stultz

alarmtimers: Change alarmtimer functions to return alarmtimer_restart values

2011-08-10T21:55:20+00:00

In order to properly fix the denial of service issue with high freq
periodic alarm timers, we need to push the re-arming logic into the
alarm timer handler, much as the hrtimer code does.

This patch introduces alarmtimer_restart enum and changes the
alarmtimer handler declarations to use it as a return value. Further,
to ease following changes, it extends the alarmtimer handler functions
to also take the time at expiration. No logic is yet modified.

CC: Thomas Gleixner 
Signed-off-by: John Stultz