[alsa-devel] HD-audio runtime PM
mengdong.lin at intel.com
Wed Nov 27 10:37:17 CET 2013
> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Tuesday, November 26, 2013 4:26 PM
> > > > -----Original Message-----
> > > > From: Takashi Iwai [mailto:tiwai at suse.de]
> > > > Sent: Tuesday, November 26, 2013 2:14 PM
> > > > To: Wang Xingchao
> > >
> > > > > I test WAKEEN feature on Haswell machines before, it could
> > > > > really wakeup system from D3.
> > > >
> > > > But the runtime suspend doesn't power down to D3 by itself.
> > > > Did you test really with D3?
> > >
> > > I will double check this on Haswell with sound git tree for-linus branch.
> > > We've tried Android on Haswell-ULT last week, the display HD-A
> controller can enter D3 and HDMI cable plug-in can wake up the controller
> and codec. The code base is v3.9 with various driver patches.
> > Hrm, but as I mentioned, we have no D3 call in runtime suspend
> > callback. How does it reach to D3 then? Maybe that part is patched
> > in your side?
I've checked two Haswell-ULT platforms with sound git tree for-linus branch, under Ubuntu:
- ELD cannot refresh properly.
- HDMI hot-plug cannot wake up the audio controller.
The controller is suspended when idle timeout and put in D3 by PCI driver. Here is the status shown by lspci -vvvv as root:
00:03.0 Audio device: Intel Corporation Device 0a0c (rev 09)
Capabilities:  Power Management version 2
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D3 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
... Status: D3 mean the device is in D3.
I guess maybe the latest display driver does not handle hot-plug properly which affect both ELD and device wakeup.
For Android on Haswell, the kernel code base and BIOS are different.
I'll further check this issue. Is it very urgent?
I cannot work full time on this now due to some timing optimization task for Baytrail at the same time.
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