Re: [PATCH 1/2] rtc-cmos: Clear expired alarm after resume

From	Gabriele Mazzotta <gabriele.mzt@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/2] rtc-cmos: Clear expired alarm after resume
Date	2016-08-25 17:50 +0200
Message-ID	<sa54J-2ST-3@gated-at.bofh.it> (permalink)
References	<rFgz8-1Kx-21@gated-at.bofh.it> <rGl3H-2ms-5@gated-at.bofh.it> <rGn5v-3xT-15@gated-at.bofh.it> <rGnRU-43r-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 04/06/2016 19:48, Alexandre Belloni wrote:
> On 04/06/2016 at 18:58:59 +0200, Gabriele Mazzotta wrote :
>> 2016-06-04 16:46 GMT+02:00 Alexandre Belloni
>> <alexandre.belloni@free-electrons.com>:
>>> On 01/06/2016 at 17:40:14 +0200, Gabriele Mazzotta wrote :
>>>> If the system wakes up because of a wake alarm, the internal state
>>>> of the alarm is not updated. As consequence, the state no longer
>>>> reflects the actual state of the hardware and setting a new alarm
>>>> is not possible until the expired alarm is cleared.
>>>>
>>>
>>> I'm not completely sure to understand what is happening but could you
>>> check whether that one is solved by
>>> 2b2f5ff00f63847d95adad6289bd8b05f5983dd5 in my tree (rtc-next).
>>>
>>
>> I picked 2b2f5ff00f63847d95adad6289bd8b05f5983dd5 and applied it
>> on top of 4.7-rc1, but that didn't fix the problem.
>>
>> Let me explain the problem by showing you how I reproduce it:
>>
>> root@localhost:~# cat /proc/driver/rtc | grep alarm_IRQ
>> alarm_IRQ       : no
>> root@localhost:~# echo +10 > /sys/class/rtc/rtc0/wakealarm
>> root@localhost:~# echo mem > /sys/power/state  # wait for auto-resume
>> root@localhost:~# echo +10 > /sys/class/rtc/rtc0/wakealarm
>> bash: echo: write error: Device or resource busy
>> root@localhost:~# cat /proc/driver/rtc | grep alarm_IRQ
>> alarm_IRQ       : yes
>>
>> To set another alarm, I have to first write 0 to wakealarm. After that
>> I can set what I want. This doesn't happen if the alarm fires while
>> the system is awake, it happens only if the system is suspended and
>> the alarm wakes it.
>>
>> I actually forgot to say that maybe this problem is not limited
>> to rtc-cmos and that maybe a general solution could be used.
>>
>> I've just looked better into what is causing this and the problem
>> seems to be caused by the fact that rtc_timer_do_work() is not
>> executed if the timer expires while the system is suspended.
>>
> 
> I doubt this is a driver independent issues as I don't get that
> behaviour on many other RTCs. I'll have a look.

Hi,

were you able to verify that no other driver is affect?

Gabriele

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH 1/2] rtc-cmos: Clear expired alarm after resume Gabriele Mazzotta <gabriele.mzt@gmail.com> - 2016-08-25 17:50 +0200
  Re: [PATCH 1/2] rtc-cmos: Clear expired alarm after resume Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-31 01:30 +0200
    Re: [PATCH 1/2] rtc-cmos: Clear expired alarm after resume Gabriele Mazzotta <gabriele.mzt@gmail.com> - 2016-08-31 17:10 +0200
      Re: [PATCH 1/2] rtc-cmos: Clear expired alarm after resume Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-08-31 18:10 +0200

csiph-web