[alsa-devel] regression: from 3.8 to 3.9: headphones output no sound on Intel HDA, codec VIA VT1802

[Takashi Iwai]

At Sun, 12 May 2013 11:53:41 +0200,
Alex Riesen wrote:
> 
> Hi,
> 
> I just noticed (use the headphones rarely) that the headphones on this
> System76 Lemur Ultra (lemu4) stopped working. There is absolutely no
> output.
> 
> I tried reverting all changes to patch_via.c since v3.8, and
> have the sound back, but there wasn't much to revert:
> 
> Revert "ALSA: hda - Rearrange INPUT_PIN_ATTR_*"
> Revert "ALSA: hda - Use generic parser for VIA codec driver"
> Revert "ALSA: hda - Enable parsing the independent HP mode as default
> for VIA codecs"
> Revert "ALSA: hda/via - Fix wrong checks of power state bits"
> Revert "ALSA: hda - Fix phantom jacks on VT1708"
> Revert "ALSA: hda - detect jacks on VT1708 even when no streams are active"
> Revert "ALSA: hda - Use generic array for loopback list management"
> 
> and one change (which I indeed suspect) is large: the use of generic parser.
> 
> The problem is also present in 3.10-rc1. The output of alsa-info.sh attached,
> for 3.8.12 and 3.9.2 respectively.

It's strange that the pin 0x25 shows EAPD 0x00 and pin-control 0x00.
They should be 0x02 and 0xc0 constantly.  Is it taken at the moment
the headphone is plugged, right?  Please give alsa-info.sh outputs at
both the headphone plugged and unplugged.

Could you check whether changing them makes the headphone output
working?  For example, get hda-verb program (see
Documentation/sound/alsa/HD-Audio.txt) and run it like

	hda-verb /dev/snd/hwC0D0 0x25 SET_PIN_WID 0xc0
	hda-verb /dev/snd/hwC0D0 0x25 SET_EAPD 0x02


thanks,

Takashi