[alsa-devel] [PATCH v3 0/2] Disable the ThinkPad HW mute/level control when possible

[Andy Lutomirski]

On Thu, Dec 4, 2014 at 3:55 AM, Darren Hart <dvhart at infradead.org> wrote:
> On Fri, Oct 17, 2014 at 05:04:28PM -0700, Andy Lutomirski wrote:
>> This series is being resurrected after several years, and it's quite
>> different from before, so I'm restarting the version numbers :)
>>
>> ThinkPad volume and mute controls are a mess.  For whatever reason,
>> ThinkPads have mute buttons that send KEY_MUTE *and* control an
>> invisible-to-ALSA mute switch.  Some of them have volume controls that
>> interact with this switch as well.
>>
>> This is a perennial source of problems.  On most ThinkPads, if you press
>> mute and then unmute using GUI controls, you have no sound, because
>> userspace and ALSA state gets out of sync with the hardware switch.
>> There's a separate "sound card" that exposes the hardware switch, but
>> userspace code generally doesn't understand that.
>>
>> There are already a few _OSI(Linux) overrides to turn all the hardware
>> buttons into regular buttons.  Rather than quirking ACPI everywhere,
>> just teach thinkpad-acpi to program the buttons for full software
>> control and to disable hardware controls.  That allows us to remove the
>> ACPI quirks and have normal mute controls.  This approach should be
>> much simpler than adding even more kludgey ALSA integration for
>> questionable gain.
>>
>> Tested on an X200s (with latching mute by default) and an X220 (with
>> a mute light and toggle mute by default).  Everything works as expected.
>>
>> Changes from v2:
>>  - Don't try to change the mute mode on IBM ThinkPads.
>>  - Further minor cleanups.
>>  - Try to restore the mode on module unload.
>>
>> Changes from v1:
>>  - Simplified the code a bit.
>>  - Improved suspend/hibernate behavior.
>>
>> Andy Lutomirski (2):
>>   thinkpad-acpi: Try to use full software mute control
>>   acpi: Remove _OSI(Linux) for ThinkPads
>>
>>  drivers/acpi/blacklist.c             |  54 ----------------
>>  drivers/platform/x86/thinkpad_acpi.c | 116 ++++++++++++++++++++++++++++++++---
>>  2 files changed, 106 insertions(+), 64 deletions(-)
>
> Andy, is this the latest version?

Yes.

--Andy

>
> --
> Darren Hart
> Intel Open Source Technology Center



-- 
Andy Lutomirski
AMA Capital Management, LLC