[PATCH v8 09/39] drm/display: hdmi-state-helper: Add fallback TMDS rate validation

Cristian Ciocaltea cristian.ciocaltea at collabora.com
Thu Jul 2 07:46:22 PDT 2026


Validate the computed TMDS character rate against
connector->hdmi.max_tmds_char_rate when no driver-specific
tmds_char_rate_valid() hook is provided.

This gives HDMI connectors a common fallback for rejecting modes whose
TMDS character rate exceeds the connector limit, while still allowing
drivers with custom validation requirements to implement their own
tmds_char_rate_valid() callback.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index ce17eeefc2da..db76699093e8 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -566,6 +566,9 @@ hdmi_clock_valid(const struct drm_connector *connector,
 		status = funcs->tmds_char_rate_valid(connector, mode, clock);
 		if (status != MODE_OK)
 			return status;
+	} else if (connector->hdmi.max_tmds_char_rate) {
+		if (clock > connector->hdmi.max_tmds_char_rate)
+			return MODE_CLOCK_HIGH;
 	}
 
 	return MODE_OK;

-- 
2.54.0




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