From 5f6730a4689269240e911853403456e243513ae0 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 21 Jun 2019 14:52:46 +0100
Subject: drm/i915: Prevent dereference of engine before NULL check in error
 capture
Git-commit: 5f6730a4689269240e911853403456e243513ae0
Patch-mainline: v5.4-rc1
References: bsc#1152489

smatch caught,
drivers/gpu/drm/i915/i915_gpu_error.c:1418 gem_record_rings() warn: variable dereferenced before check 'engine' (see line 1413)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621135246.20683-1-chris@chris-wilson.co.uk
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/i915/i915_gpu_error.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1411,7 +1411,6 @@ static void gem_record_rings(struct i915
 	for (i = 0; i < I915_NUM_ENGINES; i++) {
 		struct intel_engine_cs *engine = i915->engine[i];
 		struct drm_i915_error_engine *ee = &error->engine[i];
-		struct i915_ggtt *ggtt = engine->gt->ggtt;
 		struct i915_request *request;
 		unsigned long flags;
 
@@ -1431,7 +1430,7 @@ static void gem_record_rings(struct i915
 			struct i915_gem_context *ctx = request->gem_context;
 			struct intel_ring *ring = request->ring;
 
-			ee->vm = ctx->vm ?: &ggtt->vm;
+			ee->vm = ctx->vm ?: &engine->gt->ggtt->vm;
 
 			record_context(&ee->context, ctx);