[PATCH] drm/i915/xe3lpd: Prune modes for YUV420

[Suraj Kandpal]

We only support resolution up to 4k for single pipe when using
YUV420 format so we prune these modes and restrict the plane size
at src. This is because pipe scaling will not support YUV420 scaling
for hwidth > 4096.

--v2
-Use output format to check [Ville]
-Add Bspec references
-Modify commit messge to point to why this is needed

Bspec: 49247, 50441
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index d04609460e8c..2691eeb50a26 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1419,6 +1419,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 	struct intel_display *display = to_intel_display(_connector->dev);
 	struct intel_connector *connector = to_intel_connector(_connector);
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
+	enum intel_output_format sink_format, output_format;
 	const struct drm_display_mode *fixed_mode;
 	int target_clock = mode->clock;
 	int max_rate, mode_rate, max_lanes, max_link_clock;
@@ -1452,6 +1453,14 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 						     mode->hdisplay, target_clock);
 	max_dotclk *= num_joined_pipes;
 
+	sink_format = intel_dp_sink_format(connector, mode);
+	output_format = intel_dp_output_format(connector, sink_format);
+	if (num_joined_pipes == 1) {
+		if (output_format == INTEL_OUTPUT_FORMAT_YCBCR420 &&
+		    mode->hdisplay > 4096)
+			return MODE_NO_420;
+	}
+
 	if (target_clock > max_dotclk)
 		return MODE_CLOCK_HIGH;
 
@@ -1467,11 +1476,8 @@ intel_dp_mode_valid(struct drm_connector *_connector,
 					   intel_dp_mode_min_output_bpp(connector, mode));
 
 	if (intel_dp_has_dsc(connector)) {
-		enum intel_output_format sink_format, output_format;
 		int pipe_bpp;
 
-		sink_format = intel_dp_sink_format(connector, mode);
-		output_format = intel_dp_output_format(connector, sink_format);
 		/*
 		 * TBD pass the connector BPC,
 		 * for now U8_MAX so that max BPC on that platform would be picked
-- 
2.34.1