[alsa-devel] HDA Power management.

Takashi Iwai tiwai at suse.de
Wed Aug 6 14:16:07 CEST 2008

At Tue, 05 Aug 2008 15:13:36 -0700,
Tobin Davis wrote:
> Ok, I've been studying the code for a couple of weeks now, and testing on a
> mobile type development platform with a Realtek ALC262, but I have not been
> able to get the audio codec to enter low power mode (D3).  I can see it switch
> when running that other OS.  When running, the chip draws ~400mw, but drops to
> 40mw after switching to low power mode.  How do I get it to do the same with
> the current driver?  I'm using the git tip for alsa, and 2.6.26 final kernel.
> I have tried setting the power mode to D3 using the hda-tool from Takashi, but
> the codec reverts to D0 (full power) after a second or two, even though there
> is nothing touching the audio in my test environment.

Could you show alsa-info output?  I guess some loopback switches are
turned on that prevent the power-down.


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