drm/i915/hdmi: Make the RGB fallback for "4:2:0 only" modes the last resort

Currently we take the Hail Mary RGB fallback for "4:2:0 only" modes
already during the first pass when respect_downstream_limits==true.
It seems better to try everything else first (like ignoring TMDS
clock limits) while still preferring 4:2:0, and only if everything
else has failed fall back to RGB.

Cc: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260409101539.22032-9-ville.syrjala@linux.intel.com
Tested-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
This commit is contained in:
Ville Syrjälä 2026-04-09 13:15:38 +03:00
parent 5c7a549671
commit 654f795ca9

View File

@ -2314,7 +2314,7 @@ static int intel_hdmi_compute_formats(struct intel_encoder *encoder,
respect_downstream_limits,
INTEL_OUTPUT_FORMAT_YCBCR420);
if (ret) {
if (ret && !respect_downstream_limits) {
drm_dbg_kms(display->drm,
"YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");