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

[Takashi Iwai]

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 :)

BTW, I submitted the backport of this (with another compile warning
fix) for 5.4.y shortly ago, so hopefully this one will be covered soon
later.


Takashi

> Anyways lets wait for Michal or other Fedora users to test and see from there.
> 
> Regards,
> 
> Hans
>