path: root/Documentation/laptops
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authorHenrique de Moraes Holschuh <hmh@hmh.eng.br>2009-12-15 21:51:09 -0200
committerLen Brown <len.brown@intel.com>2009-12-15 23:57:26 -0500
commita112ceee673629afc204bf6b4a4828a6143a083f (patch)
tree688f07e2ba0dd22dffb265dbb3b9bdbc818bc5a5 /Documentation/laptops
parent329e4e18dfdc552f36b0642a3de5ebfa96063666 (diff)
thinkpad-acpi: support MUTE-only ThinkPads
Lenovo removed the extra mixer since the T61 and thereabouts. Newer Lenovo models only have the mute gate function, and leave the volume control to the HDA mixer. Until a way to automatically query the firmware about its audio control capabilities is discovered (there might not be any), use a white/black list. We will likely need to ask T60 (old and new model) and Z60/Z61 users whether they have volume control to populate the black/white list. Meanwhile, provide a volume_capabilities parameter that can be used to override the defaults. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Lorne Applebaum <lorne.applebaum@gmail.com> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation/laptops')
1 files changed, 17 insertions, 2 deletions
diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt
index 96687d0106a9..bd87682103c1 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.

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