drm/i915: Add a FIXME about drrs/psr interactions

Can't review this right now due to lack of DRRS code.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Vandana Kannan <vandana.kannan@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dp.c

@@ -4104,6 +4104,11 @@ void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
 		return;
 	}
 
+	/*
+	 * FIXME: This needs proper synchronization with psr state. But really
+	 * hard to tell without seeing the user of this function of this code.
+	 * Check locking and ordering once that lands.
+	 */
 	if (INTEL_INFO(dev)->gen < 8 && intel_edp_is_psr_enabled(dev)) {
 		DRM_DEBUG_KMS("DRRS is disabled as PSR is enabled\n");
 		return;