drm/i915/hdmi: Restructure 4:2:0 vs. 4:4:4 mode validation

Restructure the HDMI mode validation to resemble the new
intel_hdmi_compute_formats(). Keeping the two in sync helps
to avoid different bugs in each.

The main difference between mode_valid() and
intel_hdmi_compute_formats() is that we don't want the
Hail Mary RGB fallback for "4:2:0 only" modes.

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/20260409101539.22032-4-ville.syrjala@linux.intel.com
Tested-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 9c241d93166c8a24383a2d85d927ce6eb6fb7b1a..79093d8fc2e61daff29de6bfa573782846155bc4 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2045,6 +2045,27 @@ intel_hdmi_sink_format_valid(struct intel_connector *connector,
        }
 }
 
+static enum drm_mode_status
+intel_hdmi_mode_valid_format(struct intel_connector *connector,
+                            const struct drm_display_mode *mode,
+                            int clock, bool has_hdmi_sink,
+                            enum intel_output_format sink_format)
+{
+       struct intel_display *display = to_intel_display(connector);
+       enum drm_mode_status status;
+
+       status = intel_hdmi_sink_format_valid(connector, mode,
+                                             has_hdmi_sink, sink_format);
+       if (status != MODE_OK)
+               return status;
+
+       status = intel_pfit_mode_valid(display, mode, sink_format, 0);
+       if (status != MODE_OK)
+               return status;
+
+       return intel_hdmi_mode_clock_valid(&connector->base, clock, has_hdmi_sink, sink_format);
+}
+
 static enum drm_mode_status
 intel_hdmi_mode_valid(struct drm_connector *_connector,
                      const struct drm_display_mode *mode)
@@ -2052,12 +2073,11 @@ intel_hdmi_mode_valid(struct drm_connector *_connector,
        struct intel_connector *connector = to_intel_connector(_connector);
        struct intel_display *display = to_intel_display(connector);
        struct intel_hdmi *hdmi = intel_attached_hdmi(connector);
+       const struct drm_display_info *info = &connector->base.display_info;
        enum drm_mode_status status;
        int clock = mode->clock;
        int max_dotclk = display->cdclk.max_dotclk_freq;
        bool has_hdmi_sink = intel_has_hdmi_sink(hdmi, connector->base.state);
-       bool ycbcr_420_only;
-       enum intel_output_format sink_format;
 
        status = intel_cpu_transcoder_mode_valid(display, mode);
        if (status != MODE_OK)
@@ -2084,36 +2104,20 @@ intel_hdmi_mode_valid(struct drm_connector *_connector,
        if (clock > 600000)
                return MODE_CLOCK_HIGH;
 
-       ycbcr_420_only = drm_mode_is_420_only(&connector->base.display_info, mode);
-
-       if (ycbcr_420_only)
-               sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
-       else
-               sink_format = INTEL_OUTPUT_FORMAT_RGB;
+       if (drm_mode_is_420_only(info, mode)) {
+               status = intel_hdmi_mode_valid_format(connector, mode, clock, has_hdmi_sink,
+                                                     INTEL_OUTPUT_FORMAT_YCBCR420);
+       } else {
+               status = intel_hdmi_mode_valid_format(connector, mode, clock, has_hdmi_sink,
+                                                     INTEL_OUTPUT_FORMAT_RGB);
 
-       status = intel_pfit_mode_valid(display, mode, sink_format, 0);
+               if (status != MODE_OK && drm_mode_is_420_also(info, mode))
+                       status = intel_hdmi_mode_valid_format(connector, mode, clock, has_hdmi_sink,
+                                                             INTEL_OUTPUT_FORMAT_YCBCR420);
+       }
        if (status != MODE_OK)
                return status;
 
-       status = intel_hdmi_mode_clock_valid(&connector->base, clock, has_hdmi_sink, sink_format);
-       if (status != MODE_OK) {
-               if (ycbcr_420_only ||
-                   !connector->base.ycbcr_420_allowed ||
-                   !drm_mode_is_420_also(&connector->base.display_info, mode))
-                       return status;
-
-               sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
-
-               status = intel_pfit_mode_valid(display, mode, sink_format, 0);
-               if (status != MODE_OK)
-                       return status;
-
-               status = intel_hdmi_mode_clock_valid(&connector->base, clock, has_hdmi_sink,
-                                                    sink_format);
-               if (status != MODE_OK)
-                       return status;
-       }
-
        return intel_mode_valid_max_plane_size(display, mode, 1);
 }