drm/i915/backlight: Honor VESA eDP backlight luminance control capability

The VESA AUX backlight fails to be enable luminance based backlight
mainpulation becaused luminance_set is false by default.
Fix it by using luminance support control capabitliy.

Fixes: e13af5166a359 ("drm/i915/backlight: Use drm helper to initialize edp backlight")
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://lore.kernel.org/r/20250823121647.275834-1-aaron.ma@canonical.com
(cherry picked from commit 72136efb875d8438c20b9c8ab72945d474933471)
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>

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 4122847..0a3a3f6 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -546,7 +546,7 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
                                     luminance_range->max_luminance,
                                     panel->vbt.backlight.pwm_freq_hz,
                                     intel_dp->edp_dpcd, &current_level, &current_mode,
-                                    false);
+                                    panel->backlight.edp.vesa.luminance_control_support);
        if (ret < 0)
                return ret;