[PATCH 0/5] [Karmic] Fix Mute button functionality on Lenovo Thinkpads

Jerone Young jerone.young at canonical.com
Sat Aug 29 16:28:32 UTC 2009

Impact: All recently Lenovo Thinkpads since the T61/X61/R61 have an
issue under Linux where the Mute key will act independent of the OS at a
hardware level. The problem though is the user never sees an OSD and
they also don't realize they are muted as their is no indicator. Also on
some Lenovo Thinkpads the mute will only work for the speakers and not
the headphones. 

LP# 281732

Lenovo put logic in the bios of all Thinkpads to query, if the OS is
"Linux", the bios will change the functionality of the mute key to be a
mute key press.

It is rather unfortunate Lenovo still doing this today. Though these
platforms are highly unlikely to get a bios update to better handle how
the mute hot key should work under Linux. Fortunately the mute key is
the only area that is affected.

Fix: The following patches are fixes by exposing the OS as Linux to
recently released Thinkpads so that the mute key will act as a mute key

Testcase: When press mute key you will see on screen display indicating
that the mute key has been pressed and the sound is muted. 

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