From 1e2ba788787c86f527eca6ffd9adb97d691a810e Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Wed, 31 May 2017 11:33:55 +0300
Subject: [PATCH] drm/i915: fix backlight invert for non-zero minimum brightness
Git-commit: 1e2ba788787c86f527eca6ffd9adb97d691a810e
Patch-mainline: v4.13-rc5
References: FATE#322643 bsc#1055900
No-fix: e9d7486eac949f2a8d121657e536c8abdd4ea088
When we started following the backlight minimum brightness in
6dda730e55f4 ("drm/i915: respect the VBT minimum backlight brightness")
we overlooked the brightness invert quirk. Even if we invert the
brightness, we need to take the min limit into account. We probably
missed this because the invert has only been required on gen4 for proper
operation.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101127
Fixes: 6dda730e55f4 ("drm/i915: respect the VBT minimum backlight brightness")
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170531083355.7898-1-jani.nikula@intel.com
(cherry picked from commit e9d7486eac949f2a8d121657e536c8abdd4ea088)
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/intel_panel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -469,7 +469,7 @@ static u32 intel_panel_compute_brightnes
if (i915.invert_brightness > 0 ||
dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
- return panel->backlight.max - val;
+ return panel->backlight.max - val + panel->backlight.min;
}
return val;