igt/kms_flip: Use the computed vblank interval for TS checking

Since the modeline may differ from actual hardware timings, do not rely
upon it but instead measure the actual and verify that it does not
change across the various flip/vblank configurations.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 22 insertions, 11 deletions

diff --git a/tests/kms_flip.c b/tests/kms_flip.c
index 74754d17..6a1549e7 100644
--- a/tests/kms_flip.c
+++ b/tests/kms_flip.c
@@ -177,6 +177,8 @@ struct test_output {
 	int seq_step;
 	unsigned int pending_events;
 	int flip_count;
+
+	double vblank_interval;
 };
 
 
@@ -579,6 +581,12 @@ static double mode_frame_time(const struct test_output *o)
 	return 1000.0 * o->kmode[0].htotal * o->kmode[0].vtotal / o->kmode[0].clock;
 }
 
+static double actual_frame_time(const struct test_output *o)
+{
+	igt_assert(o->flags & TEST_CHECK_TS);
+	return o->vblank_interval;
+}
+
 static void *vblank_wait_thread_func(void *data)
 {
 	struct test_output *o = data;
@@ -687,12 +695,12 @@ static void check_state(const struct test_output *o, const struct event_state *e
 			  es->current_seq, es->last_seq);
 	}
 
-	if ((o->flags & TEST_CHECK_TS) && (!analog_tv_connector(o))) {
+	if (o->flags & TEST_CHECK_TS) {
 		double elapsed, expected;
 
 		timersub(&es->current_ts, &es->last_ts, &diff);
 		elapsed = 1e6*diff.tv_sec + diff.tv_usec;
-		expected = (es->current_seq - es->last_seq) * mode_frame_time(o);
+		expected = (es->current_seq - es->last_seq) * actual_frame_time(o);
 
 		igt_debug("%s ts/seq: last %ld.%06ld/%u, current %ld.%06ld/%u: elapsed=%.1fus expected=%.1fus +- %.1fus, error %.1f%%\n",
 			  es->name, es->last_ts.tv_sec, es->last_ts.tv_usec, es->last_seq,
@@ -1192,17 +1200,17 @@ static void check_final_state(const struct test_output *o,
 
 	/* Verify we drop no frames, but only if it's not a TV encoder, since
 	 * those use some funny fake timings behind userspace's back. */
-	if (o->flags & TEST_CHECK_TS && !analog_tv_connector(o)) {
+	if (o->flags & TEST_CHECK_TS) {
 		int count = es->count * o->seq_step;
-		unsigned int min = mode_frame_time(o) * (count - 1);
-		unsigned int max = mode_frame_time(o) * (count + 1);
+		unsigned int min = actual_frame_time(o) * (count - 1);
+		unsigned int max = actual_frame_time(o) * (count + 1);
 
 		igt_debug("expected %d, counted %d, encoder type %d\n",
-			  (int)(elapsed / mode_frame_time(o)), count,
+			  (int)(elapsed / actual_frame_time(o)), count,
 			  o->kencoder[0]->encoder_type);
 		igt_assert_f(elapsed >= min && elapsed <= max,
 			     "dropped frames, expected %d, counted %d, encoder type %d\n",
-			     (int)(elapsed / mode_frame_time(o)), count,
+			     (int)(elapsed / actual_frame_time(o)), count,
 			     o->kencoder[0]->encoder_type);
 	}
 }
@@ -1361,10 +1369,13 @@ static void calibrate_ts(struct test_output *o, int crtc_idx)
 		 expected, mean, stddev, 100 * 6 * stddev / mean);
 	igt_assert(6 * stddev / mean < 0.005); /* 99% accuracy within 0.5% */
 
-	igt_require_f(fabs(mean - expected) < 2*stddev,
-		      "vblank interval differs from modeline! expected %.1fus, measured %1.fus +- %.3fus, difference %.1fus (%.1f sigma)\n",
-		      expected, mean, stddev,
-		      fabs(mean - expected), fabs(mean - expected) / stddev);
+	if (fabs(mean - expected) > 2*stddev) {
+		igt_warn("vblank interval differs from modeline! expected %.1fus, measured %1.fus +- %.3fus, difference %.1fus (%.1f sigma)\n",
+				expected, mean, stddev,
+				fabs(mean - expected), fabs(mean - expected) / stddev);
+	}
+
+	o->vblank_interval = mean;
 }
 
 static void run_test_on_crtc_set(struct test_output *o, int *crtc_idxs,