From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 17 May 2018 15:24:41 +0100
Subject: drm/i915/selftests: Wait longer for the old active request
Git-commit: 39d3cc03e9ddd3c7b564acd07ba1691ba817837d
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

When testing reset, we wait for 1s on the main thread for the hang to
start. Meanwhile, we continue submitting requests on all the background
threads, and we may have more threads than cores and so potentially
starve the waiter from being woken within the timeout. As the hang
timeout and the active timeouts are the same, it is hard to distinguish
which caused the timeout. Bump the active thread timeouts to 5s,
compared to the 1s timeout for the hang, so that we preferentially
report the hang timing out, while hopefully ensuring that we do at least
wake up the hang thread first before declaring the background active
timeout.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180517142442.16979-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/selftests/intel_hangcheck.c |   48 ++++++++++++++++-------
 1 file changed, 34 insertions(+), 14 deletions(-)

--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -563,6 +563,30 @@ struct active_engine {
 #define TEST_SELF	BIT(2)
 #define TEST_PRIORITY	BIT(3)
 
+static int active_request_put(struct i915_request *rq)
+{
+	int err = 0;
+
+	if (!rq)
+		return 0;
+
+	if (i915_request_wait(rq, 0, 5 * HZ) < 0) {
+		GEM_TRACE("%s timed out waiting for completion of fence %llx:%d, seqno %d.\n",
+			  rq->engine->name,
+			  rq->fence.context,
+			  rq->fence.seqno,
+			  i915_request_global_seqno(rq));
+		GEM_TRACE_DUMP();
+
+		i915_gem_set_wedged(rq->i915);
+		err = -EIO;
+	}
+
+	i915_request_put(rq);
+
+	return err;
+}
+
 static int active_engine(void *data)
 {
 	I915_RND_STATE(prng);
@@ -611,24 +635,20 @@ static int active_engine(void *data)
 		i915_request_add(new);
 		mutex_unlock(&engine->i915->drm.struct_mutex);
 
-		if (old) {
-			if (i915_request_wait(old, 0, HZ) < 0) {
-				GEM_TRACE("%s timed out.\n", engine->name);
-				GEM_TRACE_DUMP();
-
-				i915_gem_set_wedged(engine->i915);
-				i915_request_put(old);
-				err = -EIO;
-				break;
-			}
-			i915_request_put(old);
-		}
+		err = active_request_put(old);
+		if (err)
+			break;
 
 		cond_resched();
 	}
 
-	for (count = 0; count < ARRAY_SIZE(rq); count++)
-		i915_request_put(rq[count]);
+	for (count = 0; count < ARRAY_SIZE(rq); count++) {
+		int err__ = active_request_put(rq[count]);
+
+		/* Keep the first error */
+		if (!err)
+			err = err__;
+	}
 
 err_file:
 	mock_file_free(engine->i915, file);