diff options
| author | Carsten Emde <C.Emde@osadl.org> | 2012-03-15 15:56:26 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-07 16:02:12 -0700 |
| commit | ed0bff16ccb6ab0219a541f7cbf861a9118dd34b (patch) | |
| tree | 81c7c92beca41f8796f2b8ef17e3e1a40933e563 /Documentation | |
| parent | 4c4478f4b87b3cc18572d7e50063f7fd34c95c5b (diff) | |
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>
[wml: Backported to 3.4:
- Adjust context
- one more flag QUIRK_NO_PCH_PWM_ENABLE]
Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -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 0eae64cd56cf..63740dae90a0 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -993,14 +993,19 @@ 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>]]] |