Re: [PATCH] RTC: Add an alarm disable quirk

[John Stultz]

On 07/19/2013 08:13 AM, Borislav Petkov wrote:
> On Fri, Jul 19, 2013 at 04:26:28PM +0200, Borislav Petkov wrote:
> > On Fri, Jul 19, 2013 at 12:53:49AM +0200, Borislav Petkov wrote:
> > > > I assumed it was some sort of BIOS issue where any modification of the
> > > > RTC_AIE bit caused the alarm irq line to be left high(or something
> > > > like that) that triggered the immediate power-on on shutdown. But I've
> > > > not been able to dig down on this.
> > > Ha, this actually fits like an ass on a bucket (don't ask - German
> > > proverb :-)).
> > >
> > > If what you're saying is actually the case, then this explains why not
> > > writing to 0xb doesn't cause the alarm irq to fire.
> > >
> > > Btw, in the trace above we do the disabling twice. Once from
> > > rtc_timer_remove() and then again from rtc_timer_do_work().
> > >
> > > So, if we disable it once and we touch RTC_AIE again causing the second
> > > time to rearm the alarm irq, this would explain the issue. Which reminds
> > > me:
> > >
> > > Maybe we should read out the alarm interrupt first and disable it only
> > > if it is enabled - that would save us the modification of RTC_AIE. Cool,
> > > I'll try that tomorrow.
> > Well, the below seems to do the trick. But since I don't trust the BIOS
> > in any way, I'll run it a couple more days here. Btw, I think we should
> > commit this regardless, as it saves us unneeded writes:
> Nope, this doesn't help - box just rebooted. :(
>
> So I'm back to the DMI quirk patch...

So did this work some of the time, but not all? Or was the behavior 
totally unchanged with this?

thanks
-john
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