drm/i915: Shuffle DP .mode_valid() checks

Move some of the more trivial checks in the DP .mode_valid()
hooks upwards to lessen the noise amongst the more complex
checks.
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402135148.23011-3-ville.syrjala@linux.intel.com

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

@@ -1229,6 +1229,9 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		return MODE_H_ILLEGAL;
 
+	if (mode->clock < 10000)
+		return MODE_CLOCK_LOW;
+
 	fixed_mode = intel_panel_fixed_mode(connector, mode);
 	if (intel_dp_is_edp(intel_dp) && fixed_mode) {
 		status = intel_panel_mode_valid(connector, mode);
@@ -1238,9 +1241,6 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 		target_clock = fixed_mode->clock;
 	}
 
-	if (mode->clock < 10000)
-		return MODE_CLOCK_LOW;
-
 	if (intel_dp_need_bigjoiner(intel_dp, mode->hdisplay, target_clock)) {
 		bigjoiner = true;
 		max_dotclk *= 2;

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

@@ -1302,6 +1302,16 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
 	if (*status != MODE_OK)
 		return 0;
 
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK) {
+		*status = MODE_H_ILLEGAL;
+		return 0;
+	}
+
+	if (mode->clock < 10000) {
+		*status = MODE_CLOCK_LOW;
+		return 0;
+	}
+
 	max_link_clock = intel_dp_max_link_rate(intel_dp);
 	max_lanes = intel_dp_max_lane_count(intel_dp);
 
@@ -1330,17 +1340,6 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
 		*status = MODE_CLOCK_HIGH;
 		return 0;
 	}
-
-	if (mode->clock < 10000) {
-		*status = MODE_CLOCK_LOW;
-		return 0;
-	}
-
-	if (mode->flags & DRM_MODE_FLAG_DBLCLK) {
-		*status = MODE_H_ILLEGAL;
-		return 0;
-	}
-
 	if (intel_dp_need_bigjoiner(intel_dp, mode->hdisplay, target_clock)) {
 		bigjoiner = true;
 		max_dotclk *= 2;