From: Lloyd Atkinson <latkinso@codeaurora.org>
Date: Tue, 16 Jan 2018 16:26:03 -0500
Subject: drm/msm/dsi: check msm_dsi and dsi pointers before use
Git-commit: 3f0689e663524115b068258bab789dff1ddab5da
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Move null checks of pointer arguments to the beginning of the
modeset init function since they are referenced immediately
instead of after they have already been used.

Signed-off-by: Lloyd Atkinson <latkinso@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/msm/dsi/dsi.c |   24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

--- a/drivers/gpu/drm/msm/dsi/dsi.c
+++ b/drivers/gpu/drm/msm/dsi/dsi.c
@@ -196,7 +196,7 @@ int msm_dsi_modeset_init(struct msm_dsi
 	struct drm_bridge *ext_bridge;
 	int ret;
 
-	if (WARN_ON(!encoder))
+	if (WARN_ON(!encoder) || WARN_ON(!msm_dsi) || WARN_ON(!dev))
 		return -EINVAL;
 
 	msm_dsi->dev = dev;
@@ -245,20 +245,18 @@ int msm_dsi_modeset_init(struct msm_dsi
 
 	return 0;
 fail:
-	if (msm_dsi) {
-		/* bridge/connector are normally destroyed by drm: */
-		if (msm_dsi->bridge) {
-			msm_dsi_manager_bridge_destroy(msm_dsi->bridge);
-			msm_dsi->bridge = NULL;
-		}
-
-		/* don't destroy connector if we didn't make it */
-		if (msm_dsi->connector && !msm_dsi->external_bridge)
-			msm_dsi->connector->funcs->destroy(msm_dsi->connector);
-
-		msm_dsi->connector = NULL;
+	/* bridge/connector are normally destroyed by drm: */
+	if (msm_dsi->bridge) {
+		msm_dsi_manager_bridge_destroy(msm_dsi->bridge);
+		msm_dsi->bridge = NULL;
 	}
 
+	/* don't destroy connector if we didn't make it */
+	if (msm_dsi->connector && !msm_dsi->external_bridge)
+		msm_dsi->connector->funcs->destroy(msm_dsi->connector);
+
+	msm_dsi->connector = NULL;
+
 	return ret;
 }