drm/i915/backlight: Disable pps power hook for aux based backlight

Pps power hook seems to be problematic for backlight controlled via
aux channel. Disable it for such cases.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3657
Cc: stable@vger.kernel.org
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220822140836.534432-1-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_backlight.c

@@ -17,6 +17,7 @@
 #include "intel_dsi_dcs_backlight.h"
 #include "intel_panel.h"
 #include "intel_pci_config.h"
+#include "intel_pps.h"
 
 /**
  * scale - scale values from one range to another
@@ -1772,9 +1773,13 @@ void intel_backlight_init_funcs(struct intel_panel *panel)
 		panel->backlight.pwm_funcs = &i9xx_pwm_funcs;
 	}
 
-	if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP &&
-	    intel_dp_aux_init_backlight_funcs(connector) == 0)
-		return;
+	if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
+		if (intel_dp_aux_init_backlight_funcs(connector) == 0)
+			return;
+
+		if (!(dev_priv->quirks & QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK))
+			connector->panel.backlight.power = intel_pps_backlight_power;
+	}
 
 	/* We're using a standard PWM backlight interface */
 	panel->backlight.funcs = &pwm_bl_funcs;

drivers/gpu/drm/i915/display/intel_dp.c

@@ -5303,8 +5303,6 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 
 	intel_panel_init(intel_connector);
 
-	if (!(dev_priv->quirks & QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK))
-		intel_connector->panel.backlight.power = intel_pps_backlight_power;
 	intel_backlight_setup(intel_connector, pipe);
 
 	intel_edp_add_properties(intel_dp);