diff mbox series

[v10,20/69] drm/display: hdmi-state-helper: Add source TMDS rate validation

Message ID 20260731-dw-hdmi-qp-scramb-v10-20-294364b2cf15@collabora.com (mailing list archive)
State New
Headers
Series Add HDMI 2.0 support to DW HDMI QP TX |

Commit Message

Cristian Ciocaltea July 31, 2026, 4:19 p.m. UTC 
Validate the computed TMDS character rate against
connector->hdmi.max_tmds_char_rate, when provided by the driver/source.

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

Tested-by: Maud Spierings <maud_spierings@hotmail.com>
Tested-by: Diederik de Haas <diederik@cknow-tech.com>  # NanoPC-T6 LTS, Rock 5B
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Maxime Ripard Aug. 13, 2026, 1:35 p.m. UTC | #1 
On Fri, 31 Jul 2026 19:19:27 +0300, Cristian Ciocaltea wrote:
> Validate the computed TMDS character rate against
> connector->hdmi.max_tmds_char_rate, when provided by the driver/source.
> 
> This gives HDMI connectors common support for rejecting modes whose TMDS
> character rate exceeds the source supported limit, while still allowing
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime
diff mbox series

Patch

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index ce17eeefc2da..92be6278ea44 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -560,6 +560,10 @@  hdmi_clock_valid(const struct drm_connector *connector,
 	if (info->max_tmds_clock && clock > info->max_tmds_clock * 1000)
 		return MODE_CLOCK_HIGH;
 
+	if (connector->hdmi.max_tmds_char_rate &&
+	    clock > connector->hdmi.max_tmds_char_rate)
+		return MODE_CLOCK_HIGH;
+
 	if (funcs && funcs->tmds_char_rate_valid) {
 		enum drm_mode_status status;