[PATCH 2/2] drm/i915/backlight: Modify condition to use panel luminance

[Suraj Kandpal]

According to our internal spec we need to now check if both
panel luminance and smooth brightness are available in panel for
us to be able to change brightness using luminance value.

--v2
-Add Fixes tag [Ankit]

Fixes: 64481497924d ("drm/i915/backlight: Check Luminance based brightness control for VESA")
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 8173de8aec63..20ab90acb351 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -663,7 +663,8 @@ intel_dp_aux_supports_vesa_backlight(struct intel_connector *connector)
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
 	struct intel_panel *panel = &connector->panel;
 
-	if ((intel_dp->edp_dpcd[3] & DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE)) {
+	if ((intel_dp->edp_dpcd[3] & DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE) &&
+	    (intel_dp->edp_dpcd[3] & DP_EDP_SMOOTH_BRIGHTNESS_CAPABLE)) {
 		drm_dbg_kms(display->drm,
 			    "[CONNECTOR:%d:%s] AUX Luminance Based Backlight Control Supported!\n",
 			    connector->base.base.id, connector->base.name);
-- 
2.34.1