[Bug 56203] No sound after changing volume while playing sound on an Intel 82801G (AD1986A)

[Mart Raudsepp]

Public bug reported:

Having sound problems on a computer with that sound card.

Sound becomes inaudible when changing the volume of some channels (Headphones, PCM, Front, CD, Mono, etc - not "Surround" or such things in alsamixer) while playing an audio stream (say, a video file with sound in mplayer, or aplay of a wave file). Changing any of the affecting channels makes the sound be inaudible immediately (don't have to change a couple of those, just changing one does it).
The sound becomes audible again after I change the volume of Headphones (new name for Master?) or PCM _while_ no audio is playing (inaudibly) - all audio streams are stopped. Sometimes changing the volume of Headphones helps, sometimes PCM - maybe sometimes either. But worth noting is that in some cases changing the volume of one of them doesn't help, while in other cases changing the other one doesn't help. But changing both of them or either of them always brings back sound (assuming no audio was playing at the time).
It appears that while changing the volume of other channels while audio is playing makes the sound go inaudible, only changing Headphones or Master while no audio stream is playing brings it back. Never have managed to bring it back by changing different channel volumes.

When I manage to make it work again with changing the PCM or Headphones
volume, I hear a little distinguishable sound from my headphones - same
as I hear when ctrl+C'ing on a wave playing, or changing the volume one
notch after getting the sound audible.

Sorry for the long chatter. Not sure how to sum it up better.
The problem and symptoms happen on both Dapper and also on Edgy after a dist-upgrade yesterday.

Some details:

$ tail -2 /proc/asound/oss/sndstat
Mixers:
0: Analog Devices AD1986A

lspci -v:
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)
        Subsystem: ASUSTeK Computer Inc. Unknown device 817f
        Flags: bus master, fast devsel, latency 0, IRQ 177
        Memory at e2df8000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: [50] Power Management version 2
        Capabilities: [60] Message Signalled Interrupts: 64bit+ Queue=0/0 Enable-
        Capabilities: [70] Express Unknown type IRQ 0


This is not on my computer, but on someone elses I installed Ubuntu on for them. I have non-periodic access to it (not in my town) about once a month or bi-monthly. Owners are regular computer owners who will not be able to provide more details - I will provide some more details today, and if necessary more on request once I have any kind of access to the machine again.

** Affects: alsa-driver (Ubuntu)
     Importance: Untriaged
         Status: Unconfirmed
** Affects: linux-source-2.6.15 (Ubuntu)
     Importance: Low
         Status: Needs Info

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No sound after changing volume while playing sound on an Intel 82801G (AD1986A)
https://launchpad.net/bugs/56203