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Diffstat (limited to 'Documentation/laptops/thinkpad-acpi.txt')
| -rw-r--r-- | Documentation/laptops/thinkpad-acpi.txt | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt index 96687d0106a..bd87682103c 100644 --- a/Documentation/laptops/thinkpad-acpi.txt +++ b/Documentation/laptops/thinkpad-acpi.txt @@ -1098,18 +1098,31 @@ Volume control procfs: /proc/acpi/ibm/volume This feature allows volume control on ThinkPad models with a digital -volume knob, as well as mute/unmute control. The available commands are: +volume knob (when available, not all models have it), as well as +mute/unmute control. The available commands are: echo up >/proc/acpi/ibm/volume echo down >/proc/acpi/ibm/volume echo mute >/proc/acpi/ibm/volume + echo unmute >/proc/acpi/ibm/volume echo 'level <level>' >/proc/acpi/ibm/volume The <level> number range is 0 to 14 although not all of them may be distinct. The unmute the volume after the mute command, use either the -up or down command (the level command will not unmute the volume). +up or down command (the level command will not unmute the volume), or +the unmute command. + The current volume level and mute state is shown in the file. +You can use the volume_capabilities parameter to tell the driver +whether your thinkpad has volume control or mute-only control: +volume_capabilities=1 for mixers with mute and volume control, +volume_capabilities=2 for mixers with only mute control. + +If the driver misdetects the capabilities for your ThinkPad model, +please report this to ibm-acpi-devel@lists.sourceforge.net, so that we +can update the driver. + There are two strategies for volume control. To select which one should be used, use the volume_mode module parameter: volume_mode=1 selects EC mode, and volume_mode=3 selects EC mode with NVRAM backing @@ -1450,3 +1463,5 @@ Sysfs interface changelog: is deprecated and marked for removal. 0x020600: Marker for backlight change event support. + +0x020700: Support for mute-only mixers. |