linux-toradex.git/kernel/time/alarmtimer.c, branch v3.14.3

alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't exist

2013-10-18T23:23:58+00:00

Fedora Ruby maintainer reported latest Ruby doesn't work on Fedora Rawhide
on ARM. (http://bugs.ruby-lang.org/issues/9008)

Because of, commit 1c6b39ad3f (alarmtimers: Return -ENOTSUPP if no
RTC device is present) intruduced to return ENOTSUPP when
clock_get{time,res} can't find a RTC device. However this is incorrect.

First, ENOTSUPP isn't exported to userland (ENOTSUP or EOPNOTSUP are the
closest userland equivlents).

Second, Posix and Linux man pages agree that clock_gettime and
clock_getres should return EINVAL if clk_id argument is invalid.
While the arugment that the clockid is valid, but just not supported
on this hardware could be made, this is just a technicality that
doesn't help userspace applicaitons, and only complicates error
handling.

Thus, this patch changes the code to use EINVAL.

Cc: Thomas Gleixner 
Cc: Frederic Weisbecker 
Cc: stable   #3.0 and up
Reported-by: Vit Ondruch 
Signed-off-by: KOSAKI Motohiro 
[jstultz: Tweaks to commit message to include full rational]
Signed-off-by: John Stultz

alarmtimer: Export symbols of functions declared in linux/alarmtimer.h

2013-06-12T21:02:12+00:00

Export symbols so they can be used by
drivers/staging/android/alarm-dev.c if it is built as a module.
So far alarm-dev is built-in but module support is planned (see
drivers/staging/android/TODO).

Signed-off-by: Marcus Gelderie 
[jstultz: tweaked commit message, also export newly added functions]
Signed-off-by: John Stultz

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: Rename alarmtimer_remove to alarmtimer_dequeue

2012-09-24T16:38:03+00:00

Now that alarmtimer_remove has been simplified, change
its name to _dequeue to better match its paired _enqueue
function.

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: Implement minimum alarm interval for allowing suspend

2012-09-24T16:38:01+00:00

alarmtimer suspend return -EBUSY if the next alarm will fire in less
than 2 seconds.  This allows one RTC seconds tick to occur subsequent
to this check before the alarm wakeup time is set, ensuring the wakeup
time is still in the future (assuming the RTC does not tick one more
second prior to setting the alarm).

If suspend is rejected due to an imminent alarm, hold a wakeup source
for 2 seconds to process the alarm prior to reattempting suspend.

If setting the alarm incurs an -ETIME for an alarm set in the past,
or any other problem setting the alarm, abort suspend and hold a
wakelock for 1 second while the alarm is allowed to be serviced or
other hopefully transient conditions preventing the alarm clear up.

Signed-off-by: Todd Poynor 
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

alarmtimer: Don't call rtc_timer_init() when CONFIG_RTC_CLASS=n

2012-03-24T11:46:23+00:00

rtc_timer_init() is not available when CONFIG_RTC_CLASS=n. Provide a
proper wrapper in the RTC section of alarmtimer.c

Reported-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Cc: John Stultz

alarmtimer: Make sure we initialize the rtctimer

2012-03-23T23:23:12+00:00

jonghwan Choi reported seeing warnings with the alarmtimer
code at suspend/resume time, and pointed out that the
rtctimer isn't being properly initialized.

This patch corrects this issue.

Reported-by: jonghwan Choi 
Signed-off-by: John Stultz

alarmtimers: Fix time comparison

2011-12-06T10:38:32+00:00

The expiry function compares the timer against current time and does
not expire the timer when the expiry time is >= now. That's wrong. If
the timer is set for now, then it must expire.

Make the condition expiry > now for breaking out the loop.

Signed-off-by: Thomas Gleixner 
Acked-by: John Stultz 
Cc: stable@kernel.org