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| author | Hans de Goede <hdegoede@redhat.com> | 2014-05-06 14:46:23 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-05-07 01:07:06 +0200 |
| commit | 886129a8eebebec260165741fe31421482371006 (patch) | |
| tree | 67aad5f97d72a1992db50bbcb176451b8a83ff3d /Documentation/kernel-parameters.txt | |
| parent | 43d9490244254d2d6adb0f3c6275c7b8d032a2dd (diff) | |
| download | linux-886129a8eebebec260165741fe31421482371006.tar.bz2 | |
ACPI / video: change acpi-video brightness_switch_enabled default to 0
acpi-video is unique in that it not only generates brightness up/down
keypresses, but also (sometimes) actively changes the brightness itself.
This presents an inconsistent kernel interface to userspace, basically there
are 2 different scenarios, depending on the laptop model:
1) On some laptops a brightness up/down keypress means: show a brightness osd
with the current brightness, iow it is a brightness has changed notification.
2) Where as on (a lot of) other laptops it means a brightness up/down key was
pressed, deal with it.
Most of the desktop environments interpret any press as in scenario 2, and
change the brightness up / down as a response to the key events, causing it
to be changed twice, once by acpi-video and once by the DE.
With the new default for video.use_native_backlight we will be moving even
more laptops over to behaving as in scenario 2. Making the remaining laptops
even more of a weird exception. Also note that it is hard to detect scenario
1 properly in userspace, and AFAIK none of the DE-s deals with it.
Therefor this commit changes the default of brightness_switch_enabled to 0
making its behavior consistent with all the other backlight drivers.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 43842177b771..cc2c243ac781 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3461,7 +3461,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. the allocated input device; If set to 0, video driver will only send out the event without touching backlight brightness level. - default: 1 + default: 0 virtio_mmio.device= [VMMIO] Memory mapped virtio (platform) device. |