1 files changed, 3 insertions, 84 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
index b25cd88fc1c5..d2830ba3162e 100644
--- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
@@ -173,24 +173,6 @@ static bool intel_dp_aux_set_pwm_freq(struct intel_connector *connector)
 	return true;
 }
 
-/*
-* Set minimum / maximum dynamic brightness percentage. This value is expressed
-* as the percentage of normal brightness in 5% increments.
-*/
-static bool
-intel_dp_aux_set_dynamic_backlight_percent(struct intel_dp *intel_dp,
-					   u32 min, u32 max)
-{
-	u8 dbc[] = { DIV_ROUND_CLOSEST(min, 5), DIV_ROUND_CLOSEST(max, 5) };
-
-	if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_DBC_MINIMUM_BRIGHTNESS_SET,
-			  dbc, sizeof(dbc)) < 0) {
-		DRM_DEBUG_KMS("Failed to write aux DBC brightness level\n");
-		return false;
-	}
-	return true;
-}
-
 static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_state,
 					  const struct drm_connector_state *conn_state)
 {
@@ -226,14 +208,6 @@ static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_st
 		if (intel_dp_aux_set_pwm_freq(connector))
 			new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
 
-	if (i915.enable_dbc &&
-	    (intel_dp->edp_dpcd[2] & DP_EDP_DYNAMIC_BACKLIGHT_CAP)) {
-		if(intel_dp_aux_set_dynamic_backlight_percent(intel_dp, 0, 100)) {
-			new_dpcd_buf |= DP_EDP_DYNAMIC_BACKLIGHT_ENABLE;
-			DRM_DEBUG_KMS("Enable dynamic brightness.\n");
-		}
-	}
-
 	if (new_dpcd_buf != dpcd_buf) {
 		if (drm_dp_dpcd_writeb(&intel_dp->aux,
 			DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) {
@@ -277,66 +251,15 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
 	/* Check the eDP Display control capabilities registers to determine if
 	 * the panel can support backlight control over the aux channel
 	 */
-	if ((intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
-	    (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
+	if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
+	    (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) &&
+	    !(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) {
 		DRM_DEBUG_KMS("AUX Backlight Control Supported!\n");
 		return true;
 	}
 	return false;
 }
 
-/*
- * Heuristic function whether we should use AUX for backlight adjustment or not.
- *
- * We should use AUX for backlight brightness adjustment if panel doesn't this
- * via PWM pin or using AUX is better than using PWM pin.
- *
- * The heuristic to determine that using AUX pin is better than using PWM pin is
- * that the panel support any of the feature list here.
- * - Regional backlight brightness adjustment
- * - Backlight PWM frequency set
- * - More than 8 bits resolution of brightness level
- * - Backlight enablement via AUX and not by BL_ENABLE pin
- *
- * If all above are not true, assume that using PWM pin is better.
- */
-static bool
-intel_dp_aux_display_control_heuristic(struct intel_connector *connector)
-{
-	struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
-	uint8_t reg_val;
-
-	/* Panel doesn't support adjusting backlight brightness via PWN pin */
-	if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))
-		return true;
-
-	/* Panel supports regional backlight brightness adjustment */
-	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_GENERAL_CAP_3,
-			      &reg_val) != 1) {
-		DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
-			       DP_EDP_GENERAL_CAP_3);
-		return false;
-	}
-	if (reg_val > 0)
-		return true;
-
-	/* Panel supports backlight PWM frequency set */
-	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
-		return true;
-
-	/* Panel supports more than 8 bits resolution of brightness level */
-	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
-		return true;
-
-	/* Panel supports enabling backlight via AUX but not by BL_ENABLE pin */
-	if ((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
-	    !(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP))
-		return true;
-
-	return false;
-
-}
-
 int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
 {
 	struct intel_panel *panel = &intel_connector->panel;
@@ -347,10 +270,6 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
 	if (!intel_dp_aux_display_control_capable(intel_connector))
 		return -ENODEV;
 
-	if (i915.enable_dpcd_backlight == -1 &&
-	    !intel_dp_aux_display_control_heuristic(intel_connector))
-		return -ENODEV;
-
 	panel->backlight.setup = intel_dp_aux_setup_backlight;
 	panel->backlight.enable = intel_dp_aux_enable_backlight;
 	panel->backlight.disable = intel_dp_aux_disable_backlight;