Re: REGRESSION 3.1.5: auto poweron after 5 minutes

From: Rabin Vincent
Date: Sun Dec 11 2011 - 16:22:27 EST


(CCing the lists)

On Sat, Dec 10, 2011 at 15:09:08 +0100, Andreas Friedrich wrote:
> with kernel 3.1.5 I've got a problem on my Toshiba Tecra notebook:
>
> After shuting down my system as usual, it powers on automatically
> after about 5 minutes. With kernel 3.1.4 the system stays off.
>
> After wondering around some time I read something about "ACPI RTC
> wakealarm" and found the description of your fix in the changelog of
> kernel 3.1.5:
>
> commit 0cbc008c56f7b4a11ba6fe80e196d7ab322baabf
> Author: Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>
> Date: Tue Nov 22 11:03:14 2011 +0100
>
> rtc: Disable the alarm in the hardware
>
> 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.
>
> So may be your fix caused the opposite reaction on my system. Have you
> any ideas to fix this problem?

That patch, in order to disable the alarm, calls set_alarm() on the
RTC driver with alarm->enabled as zero (and a time value that is five
minutes ahead).

Perhaps the ACPI RTC driver enables the alarm even when alarm->enable
is zero? There appears to be handling for this in rtc-cmos.c (I assume
that's what is being used) but I don't know enough about that hardware
to say if that's sufficient or not.
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