drm/radeon: Prevent hdmi deep color if max_tmds_clock is undefined.
HDMI spec requires a valid max_tmds_clock from edid for hdmi
deep color modes. If a sink violates this, disable deep color.
Also add a hint to user about the deep_color module parameter if
deep color is disabled due to that.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 19ad4fb..300c4b3 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -197,10 +197,19 @@
connector->name, bpc);
}
}
+ else if (bpc > 8) {
+ /* max_tmds_clock missing, but hdmi spec mandates it for deep color. */
+ DRM_DEBUG("%s: Required max tmds clock for HDMI deep color missing. Using 8 bpc.\n",
+ connector->name);
+ bpc = 8;
+ }
}
- if ((radeon_deep_color == 0) && (bpc > 8))
+ if ((radeon_deep_color == 0) && (bpc > 8)) {
+ DRM_DEBUG("%s: Deep color disabled. Set radeon module param deep_color=1 to enable.\n",
+ connector->name);
bpc = 8;
+ }
DRM_DEBUG("%s: Display bpc=%d, returned bpc=%d\n",
connector->name, connector->display_info.bpc, bpc);