drm/i915: Disable high-bpc on pre-1.4 EDID screens
Prevents black screens when using 30bpp framebuffers on my
HDMI screens here. The DP input on the same screen though reports a
1.4 EDID with the correct 8bpc limit set.
v2: Actually check for the right thing!
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 988e543..15ce991 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7694,6 +7694,13 @@
bpp, connector->display_info.bpc*3);
pipe_config->pipe_bpp = connector->display_info.bpc*3;
}
+
+ /* Clamp bpp to 8 on screens without EDID 1.4 */
+ if (connector->display_info.bpc == 0 && bpp > 24) {
+ DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of 24\n",
+ bpp);
+ pipe_config->pipe_bpp = 24;
+ }
}
return bpp;