[alsa-devel] [PATCH 2/2] ALSA: hda - get realtime ELD info when codec suspended

[Wang, Xingchao]

Hi David,


> -----Original Message-----
> From: alsa-devel-bounces at alsa-project.org
> [mailto:alsa-devel-bounces at alsa-project.org] On Behalf Of David Henningsson
> Sent: Tuesday, June 25, 2013 5:02 PM
> To: Wang, Xingchao
> Cc: Takashi Iwai; alsa-devel at alsa-project.org
> Subject: Re: [alsa-devel] [PATCH 2/2] ALSA: hda - get realtime ELD info when
> codec suspended
> 
> On 06/25/2013 09:55 AM, Takashi Iwai wrote:
> > At Tue, 25 Jun 2013 09:45:04 +0200,
> > David Henningsson wrote:
> >>> There is a low power mode that allows the jack detection, but this
> >>> is different from the aggressive power-saving with runtime D3.
> >>
> >> If "aggressive power-saving with runtime D3" is the same as
> >> AZX_DCAPS_PM_RUNTIME, this is also enabled for analog codecs
> >> connected to a Lynx point controller.
> >>
> >> It looks like userspace have problems getting notifications for e g
> >> headphone insertion on Lynx point controllers, so this is not only an
> >> HDMI/DP problem?
> >
> > Yes.
> >
> >> Trying to read up a little on this, there seem to be an option to set
> >> the WAKEEN register to have jack detection working even when the
> >> controller is in D3. (refer HDA specification 4.5.9.2:
> >> Codec Wake From System S0, Controller D3.) But it seems we do not
> >> (yet) use this feature. Is this something that could/should be
> >> implemented to fix the jack detection problems that seems to be
> >> happening otherwise?
> >
> > It sounds feasible, at least for traditional jack detection of analog
> > pins.  But I'm not sure whether this would help for the Intel graphics
> > case.  Just need testing.
> 
> Xingchao, what are your thoughts about using WAKEEN to wakeup both Lynx
> point and Haswell HDMI?

That's okay for me, I would do some test on that. do you have some test cases?
That would help me verify them when enable WAKEEN feature.

Thanks
--xingchao
> 
> 
> --
> David Henningsson, Canonical Ltd.
> https://launchpad.net/~diwic
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