drm/nouveau/disp: fix dithering not being enabled on some eDP macbooks

commit a6a17859f1bdf607650ee055101f54c5f207762b upstream.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
[Maarten Lankhorst backported to 3.2,
 changing nv_connector->type to nv_connector->dcb->type]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index eeaa8ca..1e72db5 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -616,7 +616,13 @@ nouveau_connector_detect_depth(struct drm_connector *connector)
        if (nv_connector->edid && connector->display_info.bpc)
                return;
 
-       /* if not, we're out of options unless we're LVDS, default to 8bpc */
+       /* EDID 1.4 is *supposed* to be supported on eDP, but, Apple... */
+       if (nv_connector->dcb->type == DCB_CONNECTOR_eDP) {
+               connector->display_info.bpc = 6;
+               return;
+       }
+
+       /* we're out of options unless we're LVDS, default to 8bpc */
        if (nv_encoder->dcb->type != OUTPUT_LVDS) {
                connector->display_info.bpc = 8;
                return;