[alsa-devel] HD-audio runtime PM

[Takashi Iwai]

At Mon, 25 Nov 2013 07:32:57 +0100,
David Henningsson wrote:
> 
> On 11/22/2013 12:57 PM, Takashi Iwai wrote:
> > Hi,
> > 
> > after my previous fix, the runtime PM seems working stably finally.
> > However, there seem still some glitches:
> > 
> > 1. The wakeup via jack or HDMI/DP detection doesn't seem to work on my
> >   test machines.  WAKEEN is set properly.  And its value can be read
> >   correctly at the point of runtime resume, too.
> 
> Hi and thanks for working on this.
> 
> I've been trying to reproduce the above, but I can't seem to activate
> runtime PM at all. I can't seem to get a callback to runtime_suspend,
> and further investigation shows that
> /sys/class/sound/card0/power/runtime_status shows "unsupported".

You need to adjust power/control of the parent PCM device,
i.e. /sys/devices/pci/*/power/control.  The following udev rule should
work for HD-audio.  Give it a try.

  ACTION=="add", SUBSYSTEM=="pci", ATTR{class}=="0x040300", TEST=="power/control", ATTR{power/control}="auto"


Takashi