[alsa-devel] kernel oops related to the new HDA audio handling for DP MST

[Hans de Goede]

Hi,

On 27-11-2019 20:27, Takashi Iwai wrote:
> On Wed, 27 Nov 2019 20:24:49 +0100,
> Takashi Iwai wrote:
>>
>> On Wed, 27 Nov 2019 19:52:37 +0100,
>> Michał Matysiak wrote:
>>>
>>> On Wed, Nov 27, 2019 at 06:00:17PM +0100, Takashi Iwai wrote:
>>>> On Wed, 27 Nov 2019 16:57:04 +0100,
>>>> Takashi Iwai wrote:
>>>>>
>>>>> On Wed, 27 Nov 2019 16:46:00 +0100,
>>>>> Hans de Goede wrote:
>>>>>>
>>>>>> Hi Takashi,
>>>>>>
>>>>>> On 27-11-2019 15:39, Takashi Iwai wrote:
>>>>>>> On Wed, 27 Nov 2019 15:26:37 +0100,
>>>>>>> Michał Matysiak wrote:
>>>>>>>>
>>>>>>>> Hi
>>>>>>>>
>>>>>>>> Recently I've encountered this error and as Hans de Goede's request I'm
>>>>>>>> reporting this back to you. This happens while booting my laptop
>>>>>>>> connected to docking station and without using one.
>>>>>>>>
>>>>>>>> kernel: WARNING: CPU: 1 PID: 330 at sound/hda/hdac_component.c:290 snd_hdac_acomp_init+0xde/0x130 [snd_hda_core]
>>>>>>>> There are 2 more "cut here", but they're almost identical so I've only
>>>>>>>> included one in this email.
>>>>>>>>
>>>>>>>> Don't know what will be valuable to you, but I'm willing to help test
>>>>>>>> this and do what I'm told. So, how can I help?
>>>>>>>>
>>>>>>>> More info about this particular kernel and issue, that led to this is at:
>>>>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1757891
>>>>>>>>
>>>>>>>> dmesg output:
>>>>>>>>
>>>>>>>> Nov 26 18:05:45 kernel: microcode: microcode updated early to revision 0x2f, date = 2019-02-17
>>>>>>>> Nov 26 18:05:45 kernel: Linux version 5.4.0-0.rc8.git0.1.rhbz1757891.fc31.x86_64 (mockbuild at buildhw-10.phx2.fedoraproject.org) (gcc version 9.2.1 20190827 (Red Hat 9.2.1-1) (GCC)) #1 SMP Wed Nov 20 14:50:34 UTC 2019
>>>>>>>> Nov 26 18:05:45 kernel: Command line: BOOT_IMAGE=(hd0,gpt2)/vmlinuz-5.4.0-0.rc8.git0.1.rhbz1757891.fc31.x86_64 root=/dev/mapper/fedora-root ro resume=/dev/mapper/fedora-swap rd.lvm.lv=fedora/root rd.luks.uuid=luks-efd8b438-8f56-405a-8cea-88f83ca38d2b rd.lvm.lv=fedora/swap rhgb quiet
>>>>>>>> ...
>>>>>>>> ...
>>>>>>>> ...
>>>>>>>> Nov 26 18:06:16 kernel: ------------[ cut here ]------------
>>>>>>>> Nov 26 18:06:16 kernel: WARNING: CPU: 0 PID: 461 at sound/hda/hdac_component.c:290 snd_hdac_acomp_init+0xde/0x130 [snd_hda_core]
>>>>>>>
>>>>>>> This should have been already fixed by the recent commit
>>>>>>> 5a858e79c911330678b5a9be91a24830e94a0dc9
>>>>>>>       ALSA: hda - Disable audio component for legacy Nvidia HDMI codecs
>>>>>>> which is already included in Linus tree.  Please check it.
>>>>>>
>>>>>> Thanks, I've started a scratch kernel build with the relevant patches added,
>>>>>> for the Fedora users hitting this to test.
>>>>>>
>>>>>> The reason they started looking into their dmesg is that their nvidia GPU (hybrid gfx setup)
>>>>>> will no longer suspend with recent kernels, this is with a 5.4 kernel which already has the
>>>>>>
>>>>>> "ALSA: hda - Force runtime PM on Nvidia HDMI codecs"
>>>>>>
>>>>>> Fix and for good measure I've already given them a test kernel with the:
>>>>>> "ALSA: hda: Allow HDA to be runtime suspended when dGPU is not bound to a drive"
>>>>>>
>>>>>> patch added. But looking at the fix for the oops I'm not sure if fixing
>>>>>> the oops is also going to fix the issue with the dGPU no longer suspending?
>>>>>
>>>>> I guess it's irrelevant with that problem, as this kernel warning (not
>>>>> really an Oops) is just about skipping the multiple audio component
>>>>> registration.  And the audio component isn't used in nouveau side on
>>>>> 5.4.x at all, and it's just a placeholder.  But who knows the black
>>>>> magic behind the scene :)
>>>>
>>>> ... and if this still doesn't fix the problem, please check the
>>>> runtime PM state of all HD-audio codec devices and HD-audio controller
>>>> device.  Do all show the runtime-suspended but the power consumption
>>>> is high?  Or is some device blocked?
>>>>
>>>> Basically the audio controller corresponding to the dGPU should have
>>>> chip->bus.keep_power = 0, which allows the runtime PM.  This flag is
>>>> cleared at azx_vx_gpu_bound() only for the dGPU.  For the primary GPU,
>>>> we need to keep the link power unless the notification is done via the
>>>> audio component (like i915 or amdgpu).  I already submitted a patch to
>>>> enable the audio component for nouveau in the past, but it's ignored,
>>>> so far.
>>>>
>>>>
>>>> thanks,
>>>>
>>>> Takashi
>>>
>>> Hi Takashi
>>>
>>> On linux-next-20191127 warning indeed disappeared. Thanks!
>>>
>>> Rest of problems did not. This is my output from alsa-info.sh
>>> http://alsa-project.org/db/?f=91bb789a01f9eed92d0534fe8951619312b355da
>>> Don't know if it's helpful, so I'll leave it here. Power consumption is
>>> high, because runtime-suspended is not enabled/active (and cannot be
>>> forced) without removing nvidia's audio.
>>
>> What if you pass power_save=1 to snd-hda-intel option?
>>
>>    echo -n 1 > /sys/module/snd_hda_intel/parameters/power_save
> 
> and the following, too:
>      echo -n 1 > /sys/module/snd_hda_intel/parameters/power_save_controller
> 
> Otherwise the controller device will keep on.

Thank you for helping us getting to the root of this.

These both default to 1 resp. Y on Fedora kernels, so I do not think
that this will help, as they are both already 1/Y.

Regards,

Hans