[alsa-devel] [PATCH 2/2] ALSA: hda/realtek - Fix Lenovo Thinkpad X1 Carbon 7th quirk value

[Benjamin Poirier]

On 2020/02/11 10:35 +0100, Jaroslav Kysela wrote:
> Dne 11. 02. 20 v 9:16 Benjamin Poirier napsal(a):
[...]
> > > 
> > > Why PA handles the rear volume control with the current driver code in the
> > > legacy ALSA driver? It should be handled like standard stereo device. I'll
> > > check.
> > 
> > The device comes up with "Analog Stereo Output" profile by default. I
> > changed it to "Analog Surround 4.0 Output" to test controlling each
> > channel individually:
> 
> Yes, but does the volume control work (does PA change the appropriate ALSA
> mixer volume)? Sometimes, it's difficult to see the difference between soft
> volume attenuation and the hardware volume control.

I see what you mean.
When set to the "Analog Surround 4.0 Output", pulseaudio didn't change
the "Bass Speaker" mixer (always at 0dB gain). It used a combination of
Master, Front and sometimes PCM mixers to control all four speakers.

For example:
pacmd list-sinks
	name: <alsa_output.pci-0000_00_1f.3.analog-surround-40>
	volume: front-left: 10349 /  16% / -48.09 dB,   front-right:
	39377 /  60% / -13.27 dB,   rear-left: 23979 /  37% / -26.20 dB,
	rear-right: 47974 /  73% / -8.13 dB
                balance 0.61
alsactl -f /tmp/output store 0
		iface MIXER
		name 'Front Playback Volume'
		value.0 33
		value.1 79
			range '0 - 87'

		name 'Bass Speaker Playback Volume'
		value.0 87
		value.1 87
			range '0 - 87'

		name 'Master Playback Volume'
		value 77
			range '0 - 87'

		name 'PCM Playback Volume'
		value.0 255
		value.1 255
			range '0 - 255'

> > > 
> > > You should also test PA with UCM.
> > 
> > Please let me know what do I need to test exactly? I'm not familiar with
> > UCM.
> 
> Just install the latest pulseaudio (latest from repo), alsa-lib and
> alsa-ucm-conf (also from repo). If pulseaudio detects UCM, it has the
> preference.

Using the packages in debian unstable, `pacmd list` shows "use_ucm=yes".
alsa-ucm-conf was already installed. Hopefully that's enough.

ii  alsa-ucm-conf    1.2.1.2-2    all          ALSA Use Case Manager configuration files
ii  libasound2:amd64 1.2.1.2-2    amd64        shared library for ALSA applications
ii  pulseaudio       13.0-5       amd64        PulseAudio sound server

pacmd list
        name: <module-alsa-card>
	argument: <device_id="0" name="pci-0000_00_1f.3"
	card_name="alsa_card.pci-0000_00_1f.3" namereg_fail=false
	tsched=yes fixed_latency_range=no ignore_dB=no
	deferred_volume=yes use_ucm=yes avoid_resampling=no
	card_properties="module-udev-detect.discovered=1">