linux-toradex.git/drivers/rtc/interface.c, branch v3.0.16

Revert "rtc: Disable the alarm in the hardware"

2012-01-06T22:14:13+00:00

commit 157e8bf8b4823bfcdefa6c1548002374b61f61df upstream.

This reverts commit c0afabd3d553c521e003779c127143ffde55a16f.

It causes failures on Toshiba laptops - instead of disabling the alarm,
it actually seems to enable it on the affected laptops, resulting in
(for example) the laptop powering on automatically five minutes after
shutdown.

There's a patch for it that appears to work for at least some people,
but it's too late to play around with this, so revert for now and try
again in the next merge window.

See for example

	http://bugs.debian.org/652869

Reported-and-bisected-by: Andreas Friedrich  (Toshiba Tecra)
Reported-by: Antonio-M. Corbi Bellot  (Toshiba Portege R500)
Reported-by: Marco Santos  (Toshiba Portege Z830)
Reported-by: Christophe Vu-Brugier   (Toshiba Portege R830)
Cc: Jonathan Nieder 
Requested-by: John Stultz 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

rtc: Disable the alarm in the hardware

2011-12-09T16:52:48+00:00

commit c0afabd3d553c521e003779c127143ffde55a16f upstream.

Currently, the RTC code does not disable the alarm in the hardware.

This means that after a sequence such as the one below (the files are in the
RTC sysfs), the box will boot up after 2 minutes even though we've
asked for the alarm to be turned off.

	# echo $((`cat since_epoch`)+120) > wakealarm
	# echo 0 > wakealarm
	# poweroff

Fix this by disabling the alarm when there are no timers to run.

Cc: John Stultz 
Signed-off-by: Rabin Vincent 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

rtc: Fix RTC PIE frequency limit

2011-10-03T18:40:08+00:00

commit 938f97bcf1bdd1b681d5d14d1d7117a2e22d4434 upstream.

Thomas earlier submitted a fix to limit the RTC PIE freq, but
picked 5000Hz out of the air. Willy noticed that we should
instead use the 8192Hz max from the rtc man documentation.

Cc: Willy Tarreau 
Cc: Thomas Gleixner 
Signed-off-by: John Stultz 
Signed-off-by: Greg Kroah-Hartman

rtc: limit frequency

2011-08-05T04:58:32+00:00

commit 431e2bcc371016824f419baa745f82388258f3ee upstream.

Due to the hrtimer self rearming mode a user can DoS the machine simply
because it's starved by hrtimer events.

The RTC hrtimer is self rearming.  We really need to limit the frequency
to something sensible.

Signed-off-by: Thomas Gleixner 
Cc: John Stultz 
Cc: Ingo Molnar 
Cc: Ben Greear 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

rtc: fix hrtimer deadlock

2011-08-05T04:58:32+00:00

commit b830ac1d9a2262093bb0f3f6a2fd2a1c8278daf5 upstream.

Ben reported a lockup related to rtc. The lockup happens due to:

CPU0                                        CPU1

rtc_irq_set_state()			    __run_hrtimer()
  spin_lock_irqsave(&rtc->irq_task_lock)    rtc_handle_legacy_irq();
					      spin_lock(&rtc->irq_task_lock);
  hrtimer_cancel()
    while (callback_running);

So the running callback never finishes as it's blocked on
rtc->irq_task_lock.

Use hrtimer_try_to_cancel() instead and drop rtc->irq_task_lock while
waiting for the callback.  Fix this for both rtc_irq_set_state() and
rtc_irq_set_freq().

Signed-off-by: Thomas Gleixner 
Reported-by: Ben Greear 
Cc: John Stultz 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

rtc: handle errors correctly in rtc_irq_set_state()

2011-08-05T04:58:32+00:00

commit 2c4f57d12df7696d65b0247bfd57fd082a7719e6 upstream.

The code checks the correctness of the parameters, but unconditionally
arms/disarms the hrtimer.

The result is that a random task might arm/disarm rtc timer and surprise
the real owner by either generating events or by stopping them.

Signed-off-by: Thomas Gleixner 
Cc: John Stultz 
Cc: Ingo Molnar 
Cc: Ben Greear 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

rtc: Staticize non-exported __rtc_set_alarm()

2011-06-02T02:29:40+00:00

It's not referenced outside this file so there's no need for it to be in
the global namespace and sparse warns about that.

Signed-off-by: Mark Brown 
Signed-off-by: John Stultz

Merge branch 'fortglx/39/tip/timers/rtc' of git://git.linaro.org/people/jstultz/linux into timers/urgent

2011-04-12T23:54:09+00:00

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

RTC: Fix early irqs caused by calling rtc_set_alarm too early

2011-03-30T01:44:05+00:00

When we register an rtc device at boot, we read the alarm value
in hardware and set the rtc device's aie_timer to that value.

The initial method to do this was to simply call rtc_set_alarm()
with the value read from hardware. However, this may cause problems
as rtc_set_alarm may enable interupts, and the RTC alarm might fire,
which can cause invalid pointer dereferencing since the RTC registration
is not complete.

This patch solves the issue by initializing the rtc_device.aie_timer
y hand via rtc_initialize_alarm(). This avoids any calls to the RTC
hardware which might enable interrupts too early.

CC: Thomas Gleixner 
CC: Alessandro Zummo 
Reported-by: Konrad Rzeszutek Wilk 
Tested-by: Konrad Rzeszutek Wilk 
Signed-off-by: John Stultz