Messages in this thread | | | Subject | Re: [Regression] 2.6.37-rc1: Lenovo T61 mute button does not work | From | Calvin Walton <> | Date | Tue, 30 Nov 2010 21:58:44 -0500 |
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On Tue, 2010-11-30 at 19:53 +0100, Lukas Hejtmanek wrote: > Hi, > > in 2.6.26, mute button worked as expected on my ThinkPad T61 - it toggled > mute with mixer applet notification. In 2.6.37-rc1, it only mutes without any > event to any mixer applet.
The mute button on this series of Thinkpads is a little weird (I have an R61i, which is the same iirc) - the behaviour of the button depends on the ACPI firmware. With no operating system running, it behaves as a persistent hardware mute. Windows apparently uses a proprietary driver to control the volume - part of this functionality has been added to the Linux thinkpad_acpi driver, but it's not fully enabled yet.
By default on this series of laptops, Linux runs with the ACPI _OSI(Linux) exported - when the bios of this laptop model sees that it's running on Linux, it disables the hardware mute functionality and the mute button acts as a standard keyboard key.
Search your dmesg for lines containing '_OSI(Linux)' - it should say that a BIOS query was honoured. Make sure you do not have 'acpi_osi="! Linux"' on your kernel command line.
-- Calvin Walton <calvin.walton@gmail.com>
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