drm/i915/selftests: Pretty print engine state when requests fail to start

During hangcheck testing, we try to execute requests following the GPU
reset, and in particular want to try and debug when those fail.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171009110301.21705-2-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drivers/gpu/drm/i915/selftests/intel_hangcheck.c

@@ -624,8 +624,11 @@ static int igt_wait_reset(void *arg)
 	__i915_add_request(rq, true);
 
 	if (!wait_for_hang(&h, rq)) {
+		struct drm_printer p = drm_info_printer(i915->drm.dev);
+
 		pr_err("Failed to start request %x, at %x\n",
 		       rq->fence.seqno, hws_seqno(&h, rq));
+		intel_engine_dump(rq->engine, &p);
 
 		i915_reset(i915, 0);
 		i915_gem_set_wedged(i915);
@@ -716,8 +719,12 @@ static int igt_reset_queue(void *arg)
 			__i915_add_request(rq, true);
 
 			if (!wait_for_hang(&h, prev)) {
+				struct drm_printer p = drm_info_printer(i915->drm.dev);
+
 				pr_err("Failed to start request %x, at %x\n",
 				       prev->fence.seqno, hws_seqno(&h, prev));
+				intel_engine_dump(rq->engine, &p);
+
 				i915_gem_request_put(rq);
 				i915_gem_request_put(prev);
 
@@ -818,8 +825,11 @@ static int igt_handle_error(void *arg)
 	__i915_add_request(rq, true);
 
 	if (!wait_for_hang(&h, rq)) {
+		struct drm_printer p = drm_info_printer(i915->drm.dev);
+
 		pr_err("Failed to start request %x, at %x\n",
 		       rq->fence.seqno, hws_seqno(&h, rq));
+		intel_engine_dump(rq->engine, &p);
 
 		i915_reset(i915, 0);
 		i915_gem_set_wedged(i915);