[Intel-gfx] [PATCH v4 4/6] drm/i915: Store brightness level in aux backlight driver

[Puthikorn Voravootivat]

Some panel will default to zero brightness when turning the
panel off and on again. This patch stores last brightness level
before turning off and set them back when panel is turning on.

Cc: Jani Nikula <jani.nikula at linux.intel.com>
Signed-off-by: Puthikorn Voravootivat <puthik at chromium.org>
---
 drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
index ae1b6fe67feb..f99cf0a6ae44 100644
--- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
@@ -95,6 +95,7 @@ intel_dp_aux_set_backlight(struct intel_connector *connector, u32 level)
 		DRM_DEBUG_KMS("Failed to write aux backlight level\n");
 		return;
 	}
+	connector->panel.backlight.level = level;
 }
 
 /*
@@ -150,6 +151,7 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector)
 		drm_dp_dpcd_writeb(&intel_dp->aux,
 			DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf);
 	}
+	intel_dp_aux_set_backlight(connector, connector->panel.backlight.level);
 }
 
 static void intel_dp_aux_disable_backlight(struct intel_connector *connector)
-- 
2.12.1.500.gab5fba24ee-goog