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

Wed Oct 10 16:37:31 CEST 2012

On 10/10/2012 03:39 PM, Da Fox wrote:
> Dear Ben,

Actually, it's David :-)

> 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:

After some attempts I think was able to find the culprit. Please test 
the attached patch and see if it resolves the problem.

>
> ---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
>

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic
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