[alsa-devel] HDMI LPE audio on Intel Compute Stick 2nd Gen (CHT)

[Takashi Iwai]

On Fri, 20 Oct 2017 17:54:45 +0200,
Pierre-Louis Bossart wrote:
> 
> On 10/20/17 8:45 AM, Ian W MORRISON wrote:
> >> I've just noticed that non of the kernels from v4.13 and up run on my
> >>> Intel Compute Stick (2nd gen Cherry Trail STK1AW32SC) unit and have
> >>> HDMI LPE audio working.
> >>>
> >>
> >> I have not tested HDMI in a while but I am not aware of any issues either.
> >> There were some patches recently to fix PulseAudio problems and I suppose
> >> some folks used a recent kernel?
> >>
> >>
> > It actually happened since v4.12 as now I get three HDMI LPE Audio devices
> > show up with 'aplay -l' rather than just one. Only 'device 2' works so if I
> > change the sink to use that device I get sound. So basically it can be
> > fixed in userland however I'm seeing others with different devices also
> > complaining how audio is broken and I think it is something that many users
> > don't know to fix. Is it worth looking into further or just leaving it as a
> > known issue?
> 
> I don't think it's a bug, it's a feature...
> The jack information tells you which device is connected/active, so
> userspace has all the data needed to select the right routing.

Right, it's a new feature that was recently added, for supporting
multiple HDMI/DPs.  The latest PA should be able to check the jack
detection of each port, so that it can switch to the actually
connected one.


Takashi