drm/nv50/dp: fix hack to work for macbooks booted via EFI

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nv50_sor.c b/drivers/gpu/drm/nouveau/nv50_sor.c
index c25c59386420..ffe8b483b7b0 100644
--- a/drivers/gpu/drm/nouveau/nv50_sor.c
+++ b/drivers/gpu/drm/nouveau/nv50_sor.c
@@ -318,6 +318,8 @@ nv50_sor_create(struct drm_connector *connector, struct dcb_entry *entry)
                 uint32_t tmp;
 
                 tmp = nv_rd32(dev, 0x61c700 + (or * 0x800));
+                if (!tmp)
+                        tmp = nv_rd32(dev, 0x610798 + (or * 8));
 
                 switch ((tmp & 0x00000f00) >> 8) {
                 case 8: