[pulseaudio-discuss] Dealing with the ThinkPad hardware mixer
luto at mit.edu
Mon May 23 10:59:55 PDT 2011
On Mon, May 23, 2011 at 1:50 PM, Colin Guthrie <gmane at colin.guthr.ie> wrote:
> 'Twas brillig, and Andrew Lutomirski at 23/05/11 18:21 did gyre and gimble:
>> What is the kernel supposed to do to get PulseAudio to DTRT? On some,
>> but not (I think) all, models, we can disable hardware mixer control
>> and make all of the buttons act like ordinary buttons, but that will
>> cause the light (if present) to malfunction, and I don't know if all
>> models can do this. So as it stands, PulseAudio would have to
>> understand that the mixer is special and watch for ALSA change
>> I'm willing to change the thinkpad-acpi driver to make it work better,
>> but I know nothing at all about PulseAudio internals. What should I
> Can you give some more details?
> e.g. does it show up under the same alsa card as the HDA or is it separate?
> amixer -c0 (or appropriate number) would be useful to begin with :)
It's separate. I can send details when I get home, but from memory:
alsamixer -c1 sees the HDA mixers.
alsamixer -c29 sees the thinkpad-acpi mixer.
On recent thinkpads with my pending thinkpad-acpi changes, alsamixer
-c29 will update itself when the hardware buttons change the mixer
state. Without my patches, alsamixer won't notice.
The magic hardware mixer is a created by the thinkpad-acpi driver
without any attempt to associate it with any other ALSA device on the
system. I suspect that the driver should be doing something different
(and again, I'm willing to make and submit changes, but I don't know
what it should do to make PulseAudio happy).
> Colin Guthrie
> Day Job:
> Tribalogic Limited [http://www.tribalogic.net/]
> Open Source:
> Mageia Contributor [http://www.mageia.org/]
> PulseAudio Hacker [http://www.pulseaudio.org/]
> Trac Hacker [http://trac.edgewall.org/]
> pulseaudio-discuss mailing list
> pulseaudio-discuss at mail.0pointer.de
More information about the pulseaudio-discuss