[alsa-devel] ALSA Multichannel through HDMI

Sun Dec 5 00:58:33 CET 2010

On 27.11.2010 06:53, John Ettedgui wrote:
> On Fri, Nov 26, 2010 at 7:30 AM, Anssi Hannula <anssi.hannula at iki.fi> wrote:
>> On 26.11.2010 08:00, John Ettedgui wrote:
>>> On Thu, Nov 25, 2010 at 9:56 PM, John Ettedgui <john.ettedgui at gmail.com> wrote:
>>>> On Thu, Nov 25, 2010 at 6:21 PM, John Ettedgui <john.ettedgui at gmail.com> wrote:
>>>>> On Thu, Nov 25, 2010 at 6:16 PM, Anssi Hannula <anssi.hannula at iki.fi> wrote:
>>>>>> On 26.11.2010 04:02, John Ettedgui wrote:
>>>>>>> On Thu, Nov 25, 2010 at 5:08 PM, John Ettedgui <john.ettedgui at gmail.com> wrote:
>>>>>>>> On Thu, Nov 25, 2010 at 4:59 PM, Anssi Hannula <anssi.hannula at iki.fi> wrote:
>>>>>>>>> On 26.11.2010 02:53, John Ettedgui wrote:
>>>>>>>>>> On Thu, Nov 25, 2010 at 3:34 PM, John Ettedgui <john.ettedgui at gmail.com> wrote:
>>>>>>>>>>> On Thu, Nov 25, 2010 at 3:15 PM, Anssi Hannula <anssi.hannula at iki.fi> wrote:
>>>>>>>>>>>> On 26.11.2010 01:11, John Ettedgui wrote:
>>>>>>>>>>>>> On Thu, Nov 25, 2010 at 2:58 PM, Anssi Hannula <anssi.hannula at iki.fi> wrote:
>>>>>>>>>>>>>> On 26.11.2010 00:42, John Ettedgui wrote:
>>>>>>>>>>>>>>> On Thu, Nov 25, 2010 at 11:19 AM, Anssi Hannula <anssi.hannula at iki.fi> wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Looking again at the the alsa info output you provided, I don't think I
>>>>>>>>>>>>>>>> have any great ideas. It looks like the chip simply reports that it
>>>>>>>>>>>>>>>> supports a maximum of 2 channels.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> One option could be hardcoding "chans = 8;" in generic_hdmi_build_pcms()
>>>>>>>>>>>>>>>> in sound/pci/hda/patch_hdmi.c (assuming you have the above patch and 2
>>>>>>>>>>>>>>>> channel audio works with it). However, I find it rather unlikely that it
>>>>>>>>>>>>>>>> would make any difference.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>> Anssi Hannula
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Anssi,
>>>>>>>>>>>>>>> the patch fails on my kernel, I cannot find the hda_codec_preset
>>>>>>>>>>>>>>> manually in there either.
>>>>>>>>>>>>>>> Did you want me to try that against a 2.6.37 rc instead of a 2.6.36?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> For 2.6.36 I think you can just use your earlier patch.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Note that on that kernel generic_hdmi_build_pcms() is
>>>>>>>>>>>>>> intel_hdmi_build_pcms() in patch_intelhdmi.c.
>>>>>>>>>>>>>>
>>>>>>>>>>>>> ok
>>>>>>>>>>>>>> BTW, I've just been informed by another ATI user that his card was
>>>>>>>>>>>>>> actually stereo-only, while he thought earlier it was multichannel
>>>>>>>>>>>>>> capable. So, are you sure your card is a multichannel one?
>>>>>>>>>>>>>> (if not, it would explain why the card says it is not)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> Anssi Hannula
>>>>>>>>>>>>>>
>>>>>>>>>>>>> Yes, it works fine in Window  so I believe the hardware part is good.
>>>>>>>>>>>>
>>>>>>>>>>>> And you are sure it is multichannel PCM, and not e.g. multichannel DTS
>>>>>>>>>>>> or multichannel AC-3 with on-the-fly compression, which are possible
>>>>>>>>>>>> with stereo hdmi as well?
>>>>>>>>>>>>
>>>>>>>>>>>> Just making sure :)
>>>>>>>>>>>>
>>>>>>>>>>>> --
>>>>>>>>>>>> Anssi Hannula
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Well, I have not super tested it, but the reason I believe it is is
>>>>>>>>>>> simple, when I use passthrough my receiver says Dolby digital or
>>>>>>>>>>> something like that, but in Windows just going around or playing games
>>>>>>>>>>> it says Multichannel.
>>>>>>>>>
>>>>>>>>> Sounds ok then.
>>>>>>>>>
>>>>>>>>>>> I'll get the patch applied in a few minutes, I was running out of
>>>>>>>>>>> memory and my system was getting really slow... :)
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> I am not sure if I did it right but now I don't even get hdmi sound
>>>>>>>>>> working anymore.
>>>>>>>>>> It is not listed in aplay-l, and dmesg gives me this:
>>>>>>>>>> [drm:radeon_dvi_detect] *ERROR* HDMI Type A-1: probed a monitor but
>>>>>>>>>> no|invalid EDID
>>>>>>>>>>
>>>>>>>>>> I've attached the patch I used, since I could not used the previous
>>>>>>>>>> one I had to hack it, maybe I broke something?
>>>>>>>>>> (I have not set channels to 8 yet, just changed the parser)
>>>>>>>>>
>>>>>>>>> The patch looks ok. The above error message is weird, as it comes from
>>>>>>>>> the display driver which should not be affected by the patch at all.
>>>>>>>>>
>>>>>>>>> I'll look at the code later (tomorrow maybe). Until then I'd advise you
>>>>>>>>> to retry without the patch and with the patch again, just to make sure
>>>>>>>>> this is not some unrelated issue...
>>>>>>>>> Also, post the whole dmesg when it works (2 channel, without patch), and
>>>>>>>>> when it doesn't (with patch).
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Anssi Hannula
>>>>>>>>>
>>>>>>>> Following your message I restarted my computer and that error was
>>>>>>>> gone, yet there is still nothing display in aplay -l / aplay -L about
>>>>>>>> hdmi anymore.
>>>>>>>> I'll go back to my non patched kernel and see what it does.
>>>>>>>>
>>>>>>> With the non-patched kernel I get back my hdmi in aplay -l, so it
>>>>>>> looks like the patch messed up something.
>>>>>>
>>>>>> Indeed.
>>>>>>
>>>>>>> I really think that when I tried it before it did not do that, but it
>>>>>>> was so long ago that I could be wrong...
>>>>>>
>>>>>> Well, the driver has changed since then, it could be more strict now :)
>>>>>>
>>>>>>> Anyway here are the 2 dmesgs (not sure if they'll help though).
>>>>>>
>>>>>> Indeed, there doesn't seem to be any difference. Maybe try with
>>>>>> CONFIG_SND_DEBUG_VERBOSE?
>>>>>>
>>>>>> --
>>>>>> Anssi Hannula
>>>>>>
>>>>>
>>>>> Sure I'll get that.
>>>>>
>>>>
>>>> There you go.
>>
>>> ALSA sound/pci/hda/hda_intel.c:2531: chipset global capabilities = 0x1001
>>> ALSA sound/pci/hda/hda_intel.c:913: codec_mask = 0x1
>>> ALSA sound/pci/hda/hda_intel.c:1354: codec #0 probed OK
>>> ALSA sound/pci/hda/hda_generic.c:683: hda_generic: no proper input path found
>>
>> Hm, for some reason it doesn't try to use the intelhdmi module. Is it
>> getting loaded? Have you run "depmod"?
>> Does "modinfo snd-hda-codec-intelhdmi" show the alias you added?
>>
>> --
>> Anssi Hannula
>>
> 
> I'm sorry it's my fault.
> I did not realize my patch was buggy, I had a white line and because
> of it the last part of the patch did not get applied.
> 
> Now aplay -l is fine, and I can use the hdmi again, but still it
> defaults to stereo.
> With a "default" asound.conf speaker-test won't allow for more than -c2.
> I tried to add channels 6 in the conf file, but it made no difference...
> 
> I will try your other suggestion.

Did you have a chance to try that?

There's no hurry, just making sure I didn't miss any message from you or
something :)

-- 
Anssi Hannula