drm/i915/selftests: Keep the engine awake while we keep for preemption

Keep the engine awake to ensure that we don't inject any pm-idle
requests.

References: https://bugs.freedesktop.org/show_bug.cgi?id=111108Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190912122639.25224-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/selftest_lrc.c

@@ -897,6 +897,10 @@ static int live_suppress_self_preempt(void *arg)
 		if (!intel_engine_has_preemption(engine))
 			continue;
 
+		if (igt_flush_test(i915, I915_WAIT_LOCKED))
+			goto err_wedged;
+
+		intel_engine_pm_get(engine);
 		engine->execlists.preempt_hang.count = 0;
 
 		rq_a = spinner_create_request(&a.spin,
@@ -904,12 +908,14 @@ static int live_suppress_self_preempt(void *arg)
 					      MI_NOOP);
 		if (IS_ERR(rq_a)) {
 			err = PTR_ERR(rq_a);
+			intel_engine_pm_put(engine);
 			goto err_client_b;
 		}
 
 		i915_request_add(rq_a);
 		if (!igt_wait_for_spinner(&a.spin, rq_a)) {
 			pr_err("First client failed to start\n");
+			intel_engine_pm_put(engine);
 			goto err_wedged;
 		}
 
@@ -921,6 +927,7 @@ static int live_suppress_self_preempt(void *arg)
 						      MI_NOOP);
 			if (IS_ERR(rq_b)) {
 				err = PTR_ERR(rq_b);
+				intel_engine_pm_put(engine);
 				goto err_client_b;
 			}
 			i915_request_add(rq_b);
@@ -931,6 +938,7 @@ static int live_suppress_self_preempt(void *arg)
 
 			if (!igt_wait_for_spinner(&b.spin, rq_b)) {
 				pr_err("Second client failed to start\n");
+				intel_engine_pm_put(engine);
 				goto err_wedged;
 			}
 
@@ -944,10 +952,12 @@ static int live_suppress_self_preempt(void *arg)
 			       engine->name,
 			       engine->execlists.preempt_hang.count,
 			       depth);
+			intel_engine_pm_put(engine);
 			err = -EINVAL;
 			goto err_client_b;
 		}
 
+		intel_engine_pm_put(engine);
 		if (igt_flush_test(i915, I915_WAIT_LOCKED))
 			goto err_wedged;
 	}