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| author | Carsten Emde <C.Emde@osadl.org> | 2012-03-15 15:56:26 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-04-25 20:25:44 +0100 |
| commit | e1eb40b7e10a98a0895aaf7c78580e89fc494375 (patch) | |
| tree | ba2661c757157adf0802b68f5e113ae84d43679e /Documentation/kernel-parameters.txt | |
| parent | f76bb07cf0f7dde553f141438261797f189ead5e (diff) | |
| download | lwn-e1eb40b7e10a98a0895aaf7c78580e89fc494375.tar.gz lwn-e1eb40b7e10a98a0895aaf7c78580e89fc494375.zip | |
drm/i915: panel: invert brightness via quirk
commit 4dca20efb1a9c2efefc28ad2867e5d6c3f5e1955 upstream.
A machine may need to invert the panel backlight brightness value. This
patch adds the infrastructure for a quirk to do so.
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d44116b70a6d..897f223dcf3e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -948,14 +948,19 @@ bytes respectively. Such letter suffixes can also be entirely omitted. i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN capability is set. - i915.invert_brightness + i915.invert_brightness= [DRM] Invert the sense of the variable that is used to set the brightness of the panel backlight. Normally a - value of 0 indicates backlight switched off, and the - maximum value sets the backlight to maximum brightness. - If this parameter is specified, a value of 0 sets the - backlight to maximum brightness, and the maximum value - switches the backlight off. + brightness value of 0 indicates backlight switched off, + and the maximum of the brightness value sets the backlight + to maximum brightness. If this parameter is set to 0 + (default) and the machine requires it, or this parameter + is set to 1, a brightness value of 0 sets the backlight + to maximum brightness, and the maximum of the brightness + value switches the backlight off. + -1 -- never invert brightness + 0 -- machine default + 1 -- force brightness inversion icn= [HW,ISDN] Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] |