[PATCH] drm/amd/display: Fix pointer dereferenced before checking

[Haowen Bai]

The pointer edid_buf is dereferencing pointer edid before edid is being
 null checked. Fix this by assigning edid->raw_edid to edid_buf only if 
edid is not NULL, otherwise just NULL.

Signed-off-by: Haowen Bai <baihaowen at meizu.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 29f07c2..360401d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -89,7 +89,7 @@ enum dc_edid_status dm_helpers_parse_edid_caps(
 {
 	struct amdgpu_dm_connector *aconnector = link->priv;
 	struct drm_connector *connector = &aconnector->base;
-	struct edid *edid_buf = (struct edid *) edid->raw_edid;
+	struct edid *edid_buf = edid ? (struct edid *) edid->raw_edid : NULL;
 	struct cea_sad *sads;
 	int sad_count = -1;
 	int sadb_count = -1;
-- 
2.7.4