[PATCH i-g-t v4 2/2] tests/kms_flip: Track and report unexpected events with pass rate metric

[Naladala Ramanaidu]

At higher refresh rates, there is a possibility of flips being
submitted during the evasion window, which can result in one extra
frame and cause the test to fail. To address this, the test has
been modified to calculate a pass rate based on the number of
expected versus erroneous frames. A threshold of 85% is enforced
to determine test success.

v1: Patch #2 and #4 merge into single patch. (Karthik)

Signed-off-by: Naladala Ramanaidu <ramanaidu.naladala at intel.com>
---
 tests/kms_flip.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/tests/kms_flip.c b/tests/kms_flip.c
index ca31ef7dd..da6fbde09 100755
--- a/tests/kms_flip.c
+++ b/tests/kms_flip.c
@@ -309,6 +309,7 @@ struct event_state {
 	unsigned int current_seq;		/* kernel reported seq. num */
 
 	int count;				/* # of events of this type */
+	int err_frames;				/* # of unexpected events */
 
 	/* Step between the current and next 'target' sequence number. */
 	int seq_step;
@@ -677,7 +678,7 @@ static void vblank_handler(int fd, unsigned int frame, unsigned int sec,
 	fixup_premature_vblank_ts(o, &o->vblank_state);
 }
 
-static bool check_state(const struct test_output *o, const struct event_state *es)
+static bool check_state(const struct test_output *o, struct event_state *es)
 {
 	struct timeval diff;
 
@@ -706,7 +707,8 @@ static bool check_state(const struct test_output *o, const struct event_state *e
 	    es->current_seq - (es->last_seq + o->seq_step) > 1UL << 23) {
 		igt_debug("unexpected %s seq %u, should be >= %u\n",
 			  es->name, es->current_seq, es->last_seq + o->seq_step);
-		return false;
+		es->err_frames++;
+		return true;
 	}
 
 	if (o->flags & TEST_CHECK_TS) {
@@ -735,8 +737,8 @@ static bool check_state(const struct test_output *o, const struct event_state *e
 			igt_debug("unexpected %s seq %u, expected %u\n",
 				  es->name, es->current_seq,
 				  es->last_seq + o->seq_step);
-
-			return false;
+			es->err_frames++;
+			return true;
 		}
 	}
 
@@ -1233,17 +1235,16 @@ static bool check_final_state(const struct test_output *o,
 	 * those use some funny fake timings behind userspace's back. */
 	if (o->flags & TEST_CHECK_TS) {
 		int count = es->count * o->seq_step;
-		unsigned int min = actual_frame_time(o) * (count - 1);
-		unsigned int max = actual_frame_time(o) * (count + 1);
+		int error_count = es->err_frames * o->seq_step;
+		int expected = elapsed / actual_frame_time(o);
+		float pass_rate = ((float)(count - error_count) / count) * 100;
 
-		igt_debug("expected %d, counted %d, encoder type %d\n",
-			  (int)(elapsed / actual_frame_time(o)), count,
-			  o->kencoder[0]->encoder_type);
-		if (elapsed < min || elapsed > max) {
-			igt_debug("dropped frames, expected %d, counted %d, encoder type %d\n",
-				  (int)(elapsed / actual_frame_time(o)), count,
-				  o->kencoder[0]->encoder_type);
+		igt_info("Event %s: expected %d, counted %d, passrate = %.2f%%, encoder type %d\n",
+			 es->name, expected, count, pass_rate, o->kencoder[0]->encoder_type);
 
+		if (pass_rate < 85) {
+			igt_debug("dropped frames, expected %d, counted %d, passrate = %.2f%%, encoder type %d\n",
+				  expected, count, pass_rate, o->kencoder[0]->encoder_type);
 			return false;
 		}
 	}
-- 
2.43.0