[alsa-devel] HD-audio runtime PM

[Takashi Iwai]

At Wed, 27 Nov 2013 09:37:17 +0000,
Lin, Mengdong wrote:
> 
> > -----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?
> 
> Hi,
> 
> 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: [50] 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?

Not that urgent, but if it's a regression, we must fix it.
If it's no regression, the urgency decreases, of course.

> I cannot work full time on this now due to some timing optimization task for Baytrail at the same time.

At least, it'd be helpful if you can confirm whether it still works
with vanilla 3.9.x kernel (or whatever version) you tested in the
past -- i.e. to know whether it's a regression or not.


thanks,

Takashi