Feature #74

Lenovo X200 Mute button mutes with the EC, not in software

Added by Nathaniel Roach almost 3 years ago. Updated about 2 years ago.

Status:NewStart date:09/19/2016
Priority:NormalDue date:
Assignee:-% Done:


Target version:-


This has the side effect of only muting the speakers, and is not toggleable.

Audio playing; press mute; muted audio (OS shows volume on still); press mute; still muted audio;

This was (in the Lenovo BIOS) toggleable with an ACPI cmdline tweak to the kernel. [1] However when I tried this a while ago it didn't work (I presume that CB doesn't replicate this behavior).

[1] https://bugzilla.kernel.org/show_bug.cgi?id=13934


#1 Updated by lx r over 2 years ago

The behaviour should be configurable. There are 2 bits reserved to configure this behaviour.
See bit 5-6 (count from 0) in 0x3 of the EC memory.
You can change those bits using ectool under coreboot.git/util/ectool.

./ectool -d
dumps the whole memory (a special buffer on the EC).

Read out the byte on 0x3 and play a little bit with bit 5-6
./ectools -w 0x3 -z 0xXX

#2 Updated by Nico Huber over 2 years ago

  • Tracker changed from Bug to Feature

#3 Updated by Arthur Heymans about 2 years ago

So do we implement an nvram parameter for this (so it is static and needs a reset/s3 cycle for it to be applied) or an ACPI method to change it during runtime with the acpi_call module or both?

#4 Updated by Patrick Rudolph about 2 years ago

The thinkpad_acpi kernel module knows about the "hardware mute" and should be able to handle it, as it's not coreboot specific. I'll do some tests on T500.

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