[alsa-devel] Bug 48381 - [Regression][Bisected]Sound gets permanently muted a few minutes after booting
da.fox.mail at gmail.com
Wed Oct 10 14:59:08 CEST 2012
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:
80c8bfbe76869bfd6bdf3d260d316e7a32f318c3 is the first bad commit
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
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
If any additional information is required please let me know.
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