Re: sound: BUG: can't load gdm greeter on battery with Linux 3.5

[Takashi Iwai <tiwai@suse.de>]

At Sun, 05 Aug 2012 14:36:19 +0200,
Vincent Blut wrote:
> 
> Hi,
> 
> Despite that the subject might suggest that this is a bug in the graphic
> stack, it appears that
> commit [b4a91cf0] makes the GDM greeter not loadable, however GDM has
> been correctly loaded:
> 
> # service gdm3 status
> [ ok ] gdm3 is running.
> 
> This issue only affects Linux 3.5 when I boot on battery, I spent some
> time to bisect and  this commit seems to be the bad one:
> 
> commit b4a91cf05c33d4ab5b2b3738a257a3fe49b462bd
> Author: Dylan Reid <dgreid@chromium.org>
> Date:   Fri Jun 15 19:36:23 2012 -0700
> 
>     ALSA: hda - Handle open while transitioning to D3.
>    
>     This addresses an issue encountered when a pcm is opened while
>     transitioning to low power state (codec->power_on == 1 &&
>     codec->power_transition == -1).  Add snd_pcm_power_up_d3wait to
>     hda_codec.  This function is used to power up from azx_open as opposed
>     to snd_hda_power_up used from codec_exec_verb. When powering up from
>     azx_open, wait for pending power downs to complete, avoiding the power
>     up continuing in parallel with the power down on the work queue.
>    
>     The specific issue seen was with the CS4210 codec, it powers off the ADC
>     and DAC nid in its suspend handler.  If it is re-opened before the
>     ~100ms power down process completes, the ADC and DAC nid are initialized
>     while powered down and audio is lost until another suspend/resume cycle.
>    
>     Signed-off-by: Dylan Reid <dgreid@chromium.org>
>     Signed-off-by: Takashi Iwai <tiwai@suse.de>
> 
> Is this a known issue?

Yes.  There is a known side-effect by this change, and the fix was
already queued for 3.5.1 stable kernel.


thanks,

Takashi