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From: Paolo Bonzini <pbonzini@redhat.com>
To: Bug 1334397 <1334397@bugs.launchpad.net>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [Bug 1334397] [NEW] cmos RTC alarms no longer wake system from suspend
Date: Wed, 25 Jun 2014 22:11:56 +0200	[thread overview]
Message-ID: <53AB2D0C.6020803@redhat.com> (raw)
In-Reply-To: <20140625183928.7492.77861.malonedeb@chaenomeles.canonical.com>

Il 25/06/2014 20:39, John Stultz ha scritto:
> Public bug reported:
>
> Running QEMU emulator version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.1),
> booting Linux kernels with qemu-system-x86_64 and qemu-system-i386, I no
> longer see the system resume from suspend when an RTC alarm is set.
>
> My simple test application can be found here:
> https://github.com/johnstultz-work/timetests/blob/master/alarmtimer-suspend.c
>
> Previously this worked w/ QEMU 1.5  (bascially up until I upgraded from
> Ubuntu 13.10 to Ubuntu 14.04, which came with 2.0).

Hi John,

I tried instrumenting QEMU and it looks like the RTC emulation is working:

cmos: write index=0x0b val=0x02
  cur 19:53:10 alarm 0:0:0
  next  alarm 14810
  cur 19:53:10 alarm 0:0:0
  next  alarm 14810
cmos: write index=0x05 val=0x19
  cur 19:53:10 alarm 19:0:0
  next  alarm 83210
cmos: write index=0x03 val=0x53
  cur 19:53:10 alarm 19:53:0
  next  alarm 86390
cmos: write index=0x01 val=0x24
  cur 19:53:10 alarm 19:53:24
  next  alarm 14
cmos: write index=0x0b val=0x22
  cur 19:53:10 alarm 19:53:24
  next  alarm 14
cmos: write index=0x0b val=0x22
  cur 19:53:10 alarm 19:53:24
  next  alarm 14
  cur 19:53:11 alarm 19:53:24
  next  alarm 13
alarm 22
  cur 19:53:24 alarm 19:53:24
  next  alarm 86400
RTC wakeup!
cmos: write index=0x0f val=0x00
cmos: write index=0x0b val=0x22
  cur 19:53:24 alarm 19:53:24
  next  alarm 86400
cmos: write index=0x0b val=0x02
  cur 19:53:24 alarm 19:53:24
  next  alarm 86400
cmos: write index=0x0b val=0x02
  cur 19:53:24 alarm 19:53:24
  next  alarm 86400
  cur 19:53:25 alarm 19:53:24
  next  alarm 86399
cmos: write index=0x0b val=0x02
  cur 19:53:25 alarm 19:53:24
  next  alarm 86399
  cur 19:53:25 alarm 19:53:24
  next  alarm 86399
cmos: write index=0x05 val=0x19
  cur 19:53:25 alarm 19:53:24
  next  alarm 86399
cmos: write index=0x03 val=0x53
  cur 19:53:25 alarm 19:53:24
  next  alarm 86399
cmos: write index=0x01 val=0x39
  cur 19:53:25 alarm 19:53:39
  next  alarm 14
cmos: write index=0x0b val=0x22
  cur 19:53:25 alarm 19:53:39
  next  alarm 14
cmos: write index=0x0b val=0x22
  cur 19:53:25 alarm 19:53:39
  next  alarm 14
  cur 19:53:26 alarm 19:53:39
  next  alarm 13
alarm 22
  cur 19:53:39 alarm 19:53:39
  next  alarm 86400
RTC wakeup!
cmos: write index=0x0f val=0x00
cmos: write index=0x0b val=0x22
  cur 19:53:39 alarm 19:53:39
  next  alarm 86400
cmos: write index=0x0b val=0x02
  cur 19:53:39 alarm 19:53:39
  next  alarm 86400
cmos: write index=0x0b val=0x02
  cur 19:53:39 alarm 19:53:39
  next  alarm 86400
  cur 19:53:40 alarm 19:53:39
  next  alarm 86399
cmos: write index=0x0b val=0x02
  cur 19:53:40 alarm 19:53:39
  next  alarm 86399
  cur 19:53:40 alarm 19:53:39
  next  alarm 86399
cmos: write index=0x05 val=0x19
  cur 19:53:40 alarm 19:53:39
  next  alarm 86399
cmos: write index=0x03 val=0x53
  cur 19:53:40 alarm 19:53:39
  next  alarm 86399
cmos: write index=0x01 val=0x54
  cur 19:53:40 alarm 19:53:54
  next  alarm 14
cmos: write index=0x0b val=0x22
  cur 19:53:40 alarm 19:53:54
  next  alarm 14

The only way to have the CMOS updated is from the guest, so the guest is 
resumed.  The "RTC wakeup!" also is just before setting the 
RT_CLOCK_STATUS field in the ACPI PM1A event status register.

However, I can reproduce that the system looks indeed like it's crashed 
and I don't see neither the resumption nor the printf from the 
sigalarm() function.  This is on kernel 3.11.10.

Also, I see that register C (the current interrupt) is always read as zero.

Right now I don't have an older QEMU, but I'll look at it tomorrow.

Paolo

  reply	other threads:[~2014-06-25 20:12 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-25 18:39 [Qemu-devel] [Bug 1334397] [NEW] cmos RTC alarms no longer wake system from suspend John Stultz
2014-06-25 20:11 ` Paolo Bonzini [this message]
2014-06-26  7:02   ` Paolo Bonzini
2014-06-26 10:01 ` Paolo Bonzini
2014-06-26 10:02 ` [Qemu-devel] [Bug 1334397] " Paolo Bonzini
2014-06-26 16:16 ` John Stultz
2014-06-26 16:56 ` John Stultz
2017-07-21 14:32 ` Thomas Huth

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