Comment 149 for bug 357673

On Thu, 18 Mar 2010, Pete Graner wrote:
> On Thu, Mar 18, 2010 at 08:12:54AM +0000, Mark Shuttleworth wrote:
> > On 17/03/10 22:22, Steve Langasek wrote:
> > > Pinging the kernel team - is this thinkpad driver backport going to
> > > happen for 10.04?
> > >
> > > ** Changed in: linux (Ubuntu Lucid)
> > > Milestone: ubuntu-10.04-beta-1 => ubuntu-10.04-beta-2
> > >
> >
> > importance high
> >
>
> After getting with apw & slangasek the patch thats needed just came
> out in the .10 stable update series. apw is building a test kernel for

(I'm the thinkpad-acpi upstream)

2.6.32.10 (and 2.6.33.1) has a lot of thinkpad-acpi fixes, but they are for
real bugs in the driver, not extra functionality. I will try to submit the
extra event functionality for backlight (not sound, which is what this bug
is about) to 2.6.32.y very soon now that the bugfix queue is empty.

2.6.32.y still doesn't have ALSA mixer support, and it will take a while for
it to be submitted to 2.6.32.y.

The ALSA stuff is not working well in mute-only thinkpads yet, the firmware
on the newer mute-only thinkpads changes behaviour depending on OSI(Linux),
and not always in the same (or sane ;-) ) way. This results in weird
behaviour and the mixer may not report properly the mute state. Using the
ALSA mixer to CHANGE mute state is not working well, either.

NOTE: I specifically do NOT recommend that the ALSA mixer be enabled in
write mode by any distro. The driver defaults to read-only mode which can
be used to get events, but the user is to use the volume hotkeys to change
volume or mute/unmute. You would do well to heed that warning.

If you guys backport this stuff from 2.6.33.1 (or current mainline), I
recommend you change the driver to disable the ALSA mixer on mute-only
thinkpads for now.

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  Henrique Holschuh