[alsa-devel] [BUG] [REGRESSION] [BISECTED] -rc1 breaks audio over HDMI for i915

[Martin Kepplinger]

Am 2016-02-12 um 14:49 schrieb Takashi Iwai:
> On Fri, 12 Feb 2016 14:09:36 +0100,
> Martin Kepplinger wrote:
>>
>> Am 2016-02-11 um 10:06 schrieb Takashi Iwai:
>>> On Wed, 10 Feb 2016 18:21:11 +0100,
>>> Martin Kepplinger wrote:
>>>>
>>>> Am 2016-02-09 um 12:44 schrieb Takashi Iwai:
>>>>> On Tue, 09 Feb 2016 07:34:48 +0100,
>>>>> Martin Kepplinger wrote:
>>>>>>
>>>>>> The following change:
>>>>>>
>>>>>> 788d441 ALSA: hda - Use component ops for i915 HDMI/DP audio jack handling
>>>>>>
>>>>>> breaks audio over HDMI on my snd_hda_intel laptop. It is the first bad
>>>>>> commit.
>>>>>>
>>>>>> This was merged for -rc1 and isn't fixed until now, so I got nervous.
>>>>>> There are
>>>>>> no errors in the log that stand out. I'm no sound or alsa developer, and
>>>>>> just reverting it isn't easy since there is stuff depending on this.
>>>>>>
>>>>>> I'm happy to test possible fixes and hope v4.5 not to ship with such a big
>>>>>> regression ;)
>>>>>
>>>>> Could you give a bit more detail about your hardware?  At best, give
>>>>> alsa-info.sh output (run with --no-upload option).  Also, give the
>>>>> output of dmesg, too.
>>>>>
>>>>> In addition, what shows /proc/asound/card*/eld#*.* files?  Does any of
>>>>> it show the proper connection state and ELD?
>>>>
>>>> alsa-info and dmesg are appended, and
>>>>
>>>> root at laptop:/home/martin/dev# cat /proc/asound/card*/eld#*
>>>> monitor_present		0
>>>> eld_valid		0
>>>
>>> OK, then could you put some debug print in intel_pin_eld_notify() in
>>> sound/pci/hda/patch_hdmi.c?  This is the callback to be called by i915
>>> driver at enabling / disabling HDMI/DP audio.
>>
>> intel_pin_eld_notify() is called during HDMI plugin with
>>
>> audio_ptr: ffff880242ea8800, port 1
>>
>> and doesn't return early.
> 
> OK, so it was processed but the ELD wasn't updated by some reason.
> 
>>> (Also, to be sure, check whether snd_hdac_i915_register_notifier() in
>>>  sound/hda/hda_i915.c is called, too.)
>>
>> snd_hdac_i915_register_notifier() is called during boot.
>>
>>>
>>> If intel_pin_eld_notify() is registered but never called, it implies
>>> something wrong in i915 driver side.  If it gets called, we need to
>>> track down: what port value was passed there, and how
>>> hdmi_present_sense() and sync_eld_via_acomp() behave there.
>>
>> I'll try to look at said path, if you have no other idea in the meantime.
> 
> Put some debug prints in sync_eld_via_acomp(), e.g. check whether
> snd_hdac_acomp_get_eld() returns an error or snd_hdmi_parse_eld()
> returns an error.  If you got an error, track down more deeply.
> 
> For example, the former function is defined in sound/hda/hdac_i915.c,
> and it calls the function i915_audio_component_get_eld() in
> drivers/gpu/drm/i915/intel_audio.c.  You can follow what returns an
> error.
> 
> Similarly, the latter function is defined in sound/pci/hda/hda_eld.c.
> Usually you see a kernel message for parse errors, so I guess this
> isn't the case, though.
> 

no error in either of the functions. size is always 0, after boot and
after HDMI plugin. is that normal?

> 
> Takashi
>