linux-toradex.git/kernel/time/alarmtimer.c, branch v3.10.94

alarmtimer: Lock k_itimer during timer callback

2014-10-05T21:54:14+00:00

commit 474e941bed9262f5fa2394f9a4a67e24499e5926 upstream.

Locks the k_itimer's it_lock member when handling the alarm timer's
expiry callback.

The regular posix timers defined in posix-timers.c have this lock held
during timout processing because their callbacks are routed through
posix_timer_fn().  The alarm timers follow a different path, so they
ought to grab the lock somewhere else.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Richard Cochran 
Cc: Prarit Bhargava 
Cc: Sharvil Nanavati 
Signed-off-by: Richard Larocque 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

alarmtimer: Do not signal SIGEV_NONE timers

2014-10-05T21:54:14+00:00

commit 265b81d23a46c39df0a735a3af4238954b41a4c2 upstream.

Avoids sending a signal to alarm timers created with sigev_notify set to
SIGEV_NONE by checking for that special case in the timeout callback.

The regular posix timers avoid sending signals to SIGEV_NONE timers by
not scheduling any callbacks for them in the first place.  Although it
would be possible to do something similar for alarm timers, it's simpler
to handle this as a special case in the timeout.

Prior to this patch, the alarm timer would ignore the sigev_notify value
and try to deliver signals to the process anyway.  Even worse, the
sanity check for the value of sigev_signo is skipped when SIGEV_NONE was
specified, so the signal number could be bogus.  If sigev_signo was an
unitialized value (as it often would be if SIGEV_NONE is used), then
it's hard to predict which signal will be sent.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Richard Cochran 
Cc: Prarit Bhargava 
Cc: Sharvil Nanavati 
Signed-off-by: Richard Larocque 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

alarmtimer: Fix bug where relative alarm timers were treated as absolute

2014-07-28T15:00:07+00:00

commit 16927776ae757d0d132bdbfabbfe2c498342bd59 upstream.

Sharvil noticed with the posix timer_settime interface, using the
CLOCK_REALTIME_ALARM or CLOCK_BOOTTIME_ALARM clockid, if the users
tried to specify a relative time timer, it would incorrectly be
treated as absolute regardless of the state of the flags argument.

This patch corrects this, properly checking the absolute/relative flag,
as well as adds further error checking that no invalid flag bits are set.

Reported-by: Sharvil Nanavati 
Signed-off-by: John Stultz 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Prarit Bhargava 
Cc: Sharvil Nanavati 
Link: http://lkml.kernel.org/r/1404767171-6902-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

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

2013-12-04T18:55:49+00:00

commit 98d6f4dd84a134d942827584a3c5f67ffd8ec35f upstream.

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 
Reported-by: Vit Ondruch 
Signed-off-by: KOSAKI Motohiro 
[jstultz: Tweaks to commit message to include full rational]
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

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