drm/edid: Set 8 bpc color depth for displays with "DFP 1.x compliant TMDS".

[cascardo/linux.git] / drivers / gpu / drm / drm_edid.c

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 2cb472b..637a0aa 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3867,6 +3867,20 @@ static void drm_add_display_info(struct edid *edid,
        /* HDMI deep color modes supported? Assign to info, if so */
        drm_assign_hdmi_deep_color_info(edid, info, connector);
 
+       /*
+        * Digital sink with "DFP 1.x compliant TMDS" according to EDID 1.3?
+        *
+        * For such displays, the DFP spec 1.0, section 3.10 "EDID support"
+        * tells us to assume 8 bpc color depth if the EDID doesn't have
+        * extensions which tell otherwise.
+        */
+       if ((info->bpc == 0) && (edid->revision < 4) &&
+           (edid->input & DRM_EDID_DIGITAL_TYPE_DVI)) {
+               info->bpc = 8;
+               DRM_DEBUG("%s: Assigning DFP sink color depth as %d bpc.\n",
+                         connector->name, info->bpc);
+       }
+
        /* Only defined for 1.4 with digital displays */
        if (edid->revision < 4)
                return;