drm/vc4: hdmi: Take the sink maximum TMDS clock into account
authorMaxime Ripard <maxime@cerno.tech>
Mon, 13 Dec 2021 14:33:11 +0000 (15:33 +0100)
committerPhil Elwell <8911409+pelwell@users.noreply.github.com>
Fri, 17 Dec 2021 13:36:14 +0000 (13:36 +0000)
In the function that validates that the clock isn't too high, we've only
taken our controller limitations into account so far.

However, the sink can have a limit on the maximum TMDS clock it can deal
with too which is exposed through the EDID and the drm_display_info.

Make sure we check it.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
drivers/gpu/drm/vc4/vc4_hdmi.c

index 8456351..a5cada0 100644 (file)
@@ -1253,12 +1253,18 @@ static enum drm_mode_status
 vc4_hdmi_encoder_clock_valid(const struct vc4_hdmi *vc4_hdmi,
                             unsigned long long clock)
 {
+       const struct drm_connector *connector = &vc4_hdmi->connector;
+       const struct drm_display_info *info = &connector->display_info;
+
        if (clock > vc4_hdmi->variant->max_pixel_clock)
                return MODE_CLOCK_HIGH;
 
        if (vc4_hdmi->disable_4kp60 && clock > HDMI_14_MAX_TMDS_CLK)
                return MODE_CLOCK_HIGH;
 
+       if (info->max_tmds_clock && clock > (info->max_tmds_clock * 1000))
+               return MODE_CLOCK_HIGH;
+
        return MODE_OK;
 }