[alsa-devel] hda-intel and runtime power-management

Takashi Iwai tiwai at suse.de
Thu Jul 28 16:27:40 CEST 2011

At Thu, 28 Jul 2011 17:21:06 +0300,
Tatulea, Dragos wrote:
> Hi,
> 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.


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