No sound on HDMI by default on Lenovo T14s using Fedora 37

[Takashi Iwai]

On Wed, 18 Jan 2023 19:45:16 +0100,
Takashi Iwai wrote:
> 
> On Wed, 18 Jan 2023 18:05:23 +0100,
> Mike FABIAN wrote:
> > 
> > Takashi Iwai <tiwai at suse.de> さんはかきました:
> > 
> > > On Wed, 18 Jan 2023 16:30:53 +0100,
> > > Mike FABIAN wrote:
> > >> 
> > >> 
> > >> With a Lenovo Thinkpad T14s (Gen1, Intel version), I tried to get sound
> > >> on the monitor speakers via the HDMI cable.
> > >> 
> > >> It didn’t work out of the box and after a bit of googling I found:
> > >> 
> > >>     https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T-series-Laptops/T14s-AMD-no-HDMI-audio-on-Linux/m-p/5081195?page=2
> > >> 
> > >> 
> > >> which suggested to put
> > >> 
> > >>     snd_rn_pci_acp3x.dmic_acpi_check=0
> > >> 
> > >> on the kernel command line.
> > >> 
> > >> So I tried this:
> > >> 
> > >> $ cat /etc/modprobe.d/lenovot14s.conf 
> > >> options snd-rn-pci-acp3x dmic_acpi_check=0
> > >> 
> > >> And that did make it work indeed.
> > >> 
> > >> I have no idea what this means and why this makes it work.
> > >
> > > The option basically should influence on the driver's behavior whether
> > > to probe the built-in d-mic or not, and it has no direct relationship
> > > with HDMI (supposedly via HD-audio bus), so it's puzzling how this
> > > fixes the problem.
> > >
> > > Could you run alsa-info.sh (with --no-upload option) on both working
> > > and non-working cases, and attach both outputs for comparison?
> > 
> > I removed /etc/modprobe.d/lenovot14s.conf but now it still works ☹
> > 
> > I did a “sudo dnf --enablerepo=updates-testing update”
> > 
> > since I last rebooted, so it is possible that an update fixed this.
> > 
> > So unfortunately I cannot produce a “alsa-info.sh --no-upload” output
> > for the non-working case anymore (I attached the output for the working
> > case *without* /etc/modprobe.d/lenovot14s.conf (i.e. without snd_rn_pci_acp3x.dmic_acpi_check=0)
> 
> Hm, I see no snd-rn-pci-acp3x module is loaded there, so something
> might prevent it loaded (e.g. blacklist or such)?
> 
> And, with this state, can you use the built-in mic?  Also, how after
> restoring the module option?

Also, maybe more fundamental question: how exactly "it didn't work"?
Does the HDMI device appear on pipewire / PulseAudio, but the output
results in silence?  Or Is no HDMI listed there?

BTW, the lack of AMD SoC stuff might be related with the device power
state.  A cold boot might change the situation (or trying back to an
older known kernel).


Takashi