[alsa-devel] Bug 48381 - [Regression][Bisected]Sound gets permanently muted a few minutes after booting

[Da Fox]

Dear Ben,

I mostly use mplayer to play audio and video files, using the 'alsa'
output driver.
I have attached the requested information to the bugtracker in full,
the following is a quick diff of the two files:

---8<---------
--- alsa-info_fresh-boot-speakers-working.txt	2012-10-10
15:31:13.787442105 +0200
+++ alsa-info_after-a-minute-speakers-NOT-working.txt	2012-10-10
15:32:29.395605762 +0200
@@ -3,7 +3,7 @@
 !!ALSA Information Script v 0.4.61
 !!################################

-!!Script ran on: Wed Oct 10 13:31:13 UTC 2012
+!!Script ran on: Wed Oct 10 13:32:28 UTC 2012


 !!Linux Distribution
@@ -275,7 +275,7 @@
     Conn = ATAPI, Color = Unknown
     DefAssociation = 0x1, Sequence = 0x0
     Misc = NO_PRESENCE
-  Pin-ctls: 0x40: OUT
+  Pin-ctls: 0x00:
   Unsolicited: tag=00, enabled=0
   Power states:  D0 D1 D2 D3 EPSS
   Power: setting=D0, actual=D0
@@ -530,7 +530,7 @@

 crw-rw---- 1 root audio 116,  6 Oct 10  2012 /dev/snd/controlC0
 crw-rw---- 1 root audio 116,  5 Oct 10  2012 /dev/snd/pcmC0D0c
-crw-rw---- 1 root audio 116,  4 Oct 10 15:30 /dev/snd/pcmC0D0p
+crw-rw---- 1 root audio 116,  4 Oct 10 15:32 /dev/snd/pcmC0D0p
 crw-rw---- 1 root audio 116,  3 Oct 10  2012 /dev/snd/pcmC0D1p
 crw-rw---- 1 root audio 116,  2 Oct 10  2012 /dev/snd/pcmC0D3p
 crw-rw---- 1 root audio 116,  1 Oct 10  2012 /dev/snd/seq
@@ -550,7 +550,7 @@

 **** List of PLAYBACK Hardware Devices ****
 card 0: PCH [HDA Intel PCH], device 0: ALC665 Analog [ALC665 Analog]
-  Subdevices: 0/1
+  Subdevices: 1/1
   Subdevice #0: subdevice #0
 card 0: PCH [HDA Intel PCH], device 1: ALC665 Digital [ALC665 Digital]
   Subdevices: 1/1
--->8---------

Best regards,
  Da Fox

On Wed, Oct 10, 2012 at 3:20 PM, David Henningsson
<david.henningsson at canonical.com> wrote:
> On 10/10/2012 02:59 PM, Da Fox wrote:
>>
>> Hi all,
>>
>> Since the official bug-tracker at
>> https://bugtrack.alsa-project.org/alsa-bug/ seems to be down (and
>> moreover this appears to be a kernel bug), I have filed a bug at the
>> kernel's bug-tracker last week (
>> https://bugzilla.kernel.org/show_bug.cgi?id=48381 ). However, it seems
>> to have gone unnoticed thus-far.
>>
>> Quick summary of the issue:
>> After a while of inactivity the sound-card seems to go into a sort of
>> power-saving mode (you can hear a faint 'pop' from the speakers).
>> Before the sound would automatically turn back on again as soon as a
>> program attempted to play sound. However now it seems that after
>> resuming from the power-saving mode the driver thinks that there is
>> always a headphone connected, even when it is not. I think this is
>> what happens because toggling the 'Auto-Mute Mode' (setting it to
>> 'Disabled') in alsamixer allows the speakers to produce sound again.
>> This is all on a laptop (please see the linked bug report for more
>> detailed hardware description).
>>
>> Would a developer please take a look at it? I have bisected the issue
>> down to a commit made by David Henningsson and/or Takashi Iwai:
>> ---8<---------
>> 80c8bfbe76869bfd6bdf3d260d316e7a32f318c3 is the first bad commit
>> commit 80c8bfbe76869bfd6bdf3d260d316e7a32f318c3
>> Author: David Henningsson <david.henningsson at canonical.com>
>> Date:   Mon Jun 4 09:33:51 2012 +0200
>>
>>      ALSA: HDA: Create phantom jacks for fixed inputs and outputs
>>
>>      PulseAudio sometimes have difficulties knowing that there is a
>>      "Speaker" or "Internal Mic", if they have no individual volume
>>      controls or selectors. As a result, only e g "Headphone" might
>>      be created for a laptop, but no "Speaker".
>>      To help out, create phantom jacks (that are always present,
>>      at least for now) for "Speaker", "Internal Mic" etc, in case we
>>      detect them.
>>      The naming convention is e g "Speaker Phantom Jack".
>>
>>      In order not to pollute the /dev/input namespace with even more
>>      devices, these are added to the kcontrols only, not the input
>> devices.
>>
>>      Signed-off-by: David Henningsson <david.henningsson at canonical.com>
>>      Signed-off-by: Takashi Iwai <tiwai at suse.de>
>>
>> :040000 040000 7a954b731bef80cee731763521f64a424a7058a0
>> 7d176b02ebb4553b0b0f97d200f7527cb69c122a M    sound
>> --->8---------
>>
>> If any additional information is required please let me know.
>
>
> Thanks for the heads up. I would need the following additional information:
>
> 1) One alsa-info taken during playback through internal speakers, when the
> internal speakers are working, and
> 2) One alsa-info taken during playback through internal speakers, when the
> internal speakers are not working.
>
> (See https://wiki.ubuntu.com/Audio/AlsaInfo if you don't know what alsa-info
> is.)
>
> If you're using PulseAudio for playback, please also include the output of
> "pacmd list" in the above two scenarios.
>
>
> --
> David Henningsson, Canonical Ltd.
> https://launchpad.net/~diwic