At Wed, 10 Aug 2011 22:34:31 +0300, Tatulea, Dragos wrote:
On Mon, Aug 8, 2011 at 9:11 AM, Takashi Iwai tiwai@suse.de wrote:
At Sun, 7 Aug 2011 20:55:52 +0300, Tatulea, Dragos wrote:
> I'm in the process of enabling pm runtime pm for the hda_intel
driver,
> not being sure if this is a sane task :). Noticed that > CONFIG_SND_HDA_POWER_SAVE disables codecs and chip when they are
not
> in use, but the power gain is not noticeable on my hw. On the other > hand, a full suspend (azx_suspend) does save a few hundred mW's. > I am aware that this is hw specific, but I would like to take > advantage of the full suspend. Suspend/resume latency is below
jiffy
> resolution.
Hm, it's strange. Basically the current power-save does almost equivalent with the normal suspend/resume, i.e. the codec is suspended and azx_stop_chip() is called. Make sure that the power-saving is really kicked in during your test.
Indeed, I checked and a codec is stuck in a power transition for some
reason.
You should check who accessing the device files via fuser, etc.
Yes, there's a non-muted pcm around there that prevents the codec from sleeping. I have a patch that checks for all substream states and puts the chip to sleep when they are all paused/suspended. Is this a bad idea? It could be that resuming the chip takes too long, depending on hw...
The PCM state check would be good.
thanks,
Takashi