Re: [PATCH v4 0/5] ALSA: hda - hdmi support dynamic pcm assignment

[Takashi Iwai <tiwai@suse.de>]

On Fri, 18 Dec 2015 11:48:49 +0100,
Takashi Iwai wrote:
> 
> On Fri, 18 Dec 2015 03:53:32 +0100,
> Yang, Libin wrote:
> > 
> > Hi Takashi,
> > 
> > > -----Original Message-----
> > > From: Takashi Iwai [mailto:tiwai@suse.de]
> > > Sent: Wednesday, December 16, 2015 3:47 PM
> > > To: libin.yang@linux.intel.com
> > > Cc: alsa-devel@alsa-project.org; Lin, Mengdong; Yang, Libin
> > > Subject: Re: [alsa-devel] [PATCH v4 0/5] ALSA: hda - hdmi support
> > > dynamic pcm assignment
> > > 
> > > On Wed, 16 Dec 2015 06:42:40 +0100,
> > > libin.yang@linux.intel.com wrote:
> > > >
> > > > From: Libin Yang <libin.yang@linux.intel.com>
> > > >
> > > > The patches are trying to support dynamically binding PCM to pin
> > > > in HDMI/DP audio.
> > > >
> > > > The pin will not bind to any PCM if there is not monitor connected.
> > > > When there is a monitor connected to the port (pin), driver will
> > > > try to find a proper PCM to assign to the port and setup the pin
> > > > if necessary.
> > > >
> > > > Libin Yang (5):
> > > >   ALSA: hda - hdmi begin to support dynamic PCM assignment
> > > >   ALSA: hda - hdmi playback without monitor in dynamic pcm bind
> > > mode
> > > >   ALSA: hda - hdmi operate spdif based on pcm
> > > >   ALSA: hda - hdmi dynamically bind PCM to pin when monitor hotplug
> > > >   ALSA: hda - hdmi setup pin when monitor hotplug in pcm dynamic
> > > >     assignment mode
> > > 
> > > I updated topic/hda-mst branch with these patches.  But the patch 4
> > > needs more fixes, as suggested in another mail.
> > > 
> > > Overall, I'd like to know whether MST audio really works in the
> > > current state, or not.  Do you have *any* git branch where MST audio
> > > is supposed to work at all?
> > 
> > I have uploaded the patches to: https://github.com/libinyang/linux.git
> > Branch is mst_virtual_pin_github. 
> > 
> > There is still an issue when doing the mst audio playback:
> > The later converter selection for pin will overwrite the previous setting.
> > This is the driver bug, I'm debugging it. 
> 
> Thanks.  I tried this branch, but the DP MST audio on my HP laptop
> dock doesn't seem working.  It gets no notification (maybe expected),
> but the accesses to any HDMI devices result in the error.  I tested
> via aplay -Dhdmi:0,0 to 0,2.
> 
> With the latest patchset (e.g. my test/hdmi-jack branch) I get the
> notification and ELD, but the audio still doesn't come out.  So,
> something seems missing.

Actually I'm thinking how the MST things are supposed to work here.
The machine here has a docking station connected to port D, and it has
to DP connectors.  Meanwhile it has a built-in DP port on port C.
The latter works fine while dock ports don't.

Suppose if I plug two monitors on the docking station.  How would the
audio in HD-audio side be set up?


thanks,

Takashi