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@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@canonical.com> Signed-off-by: Takashi Iwai <tiwai@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.