On Sat, Feb 20, 2016 at 09:12:42AM -0600, Pierre-Louis Bossart wrote:
> On 02/19/2016 02:39 PM, Giacomo Comes wrote:
> > Hi,
> > I have recently bought a Intel Compute Stick and I am having trouble with the audio.
> > Intel provides a custom Ubuntu release that support audio, but I want to run the 
> > linux distribution of my choice on it (openSUSE 13.2 for the moment).
> > 
> > In order to have HDMI audio support it is necessary to compile a kernel with this patch
> > (https://raw.githubusercontent.com/01org/baytrailaudio/master/hdmi_audio_20150319.patch)
> > provided by Intel for kernel 3.16.7 (https://01.org/ubuntu-hdmi)
> > 
> > I compiled the openSUSE kernel using the default openSUSE .config plus the following:
> > CONFIG_SUPPORT_HDMI=y
> > CONFIG_SND_SOC=m
> > CONFIG_SND_SOC_INTEL_SST=m
> > CONFIG_SND_SOC_INTEL_BYT_RT5640_MACH=m
> > 
> > I booted the new kernel and aplay -l gives this output:
> > **** List of PLAYBACK Hardware Devices ****
> > card 0: IntelHDMI [IntelHDMI], device 0: IntelHDMI [IntelHDMI]
> >   Subdevices: 0/1
> >   Subdevice #0: subdevice #0
> > 
> > but when I run:
> >   aplay /usr/share/sounds/alsa/test.wav
> > the audio plays for .2 seconds and then nothing more.
> > Sometime it will play later a little bit more and stop again.
> > At some point these messages appears:
> > underrun!!! (at least 29325.946 ms long)
> > underrun!!! (at least 1535.889 ms long)
> > underrun!!! (at least 3196.213 ms long)
> > 
> > 
> > I have looked around on google for a hint on how to fix this issue but I found nothing.
> > Any idea where to look for a solution?
> > 
> > Attached there are the dmesg and lsmod output for ubuntu
> > with the working audio and openSUSE 13.2 plus patch
> > without the working audio.
> > I can provide any other information you need.

Thank you for answering. I'm glad that at Intel you are trying to make
this work properly. I think a proper linux support for your device can only
increase his sales. I myself intend to buy at least 5 more for personal use,
and, being a system administrator, I have plan to deploy about 20 Compute Stick
in my work place. But before that happens, a better linux support is advisable.
 
> There are enough messages that make me believe something is very wrong from the start
> 
> 19.664486] had: ******** HAD DRIVER loading.. Ver: 0.01.003
> [   19.664549] hdmi_audio_probe dma_mask: 0
> [   19.664937] card->dev is NULL!!!!! Should not be this case
> [   19.668176] [drm] mid_hdmi_audio_register: Scheduling HDMI audio work queue
> [   19.670745] [drm:i915_had_wq] *ERROR* Checking for HDMI connection at boot
> 
> Some of us at Intel are trying to clean this up but it'll take time. 

I think the issue I'm having is not with the driver itself. I have followed another 
path. Instead of patching and recompiling the kernel, I have used this source:
http://oem.archive.canonical.com/updates/pool/public/o/oem-audio-i915-baytrail-dkms/oem-audio-i915-baytrail-dkms_0.20150605.tar.gz
and installed the hdmi_audio module using dkms.
After reboot the message:
  card->dev is NULL!!!!! Should not be this case
is missing (see attached dmesg output) but still when I try to play a sound aplay hangs as before.
Can anybody tell me were to look for the problem I'm having?
I suspect a configuration/initialization problem.
The same module works with the ubuntu image for the Compute Stick.

Giacomo