[PATCH i-g-t 3/3] tests/i915/kms_flip_tiling: Fix pageflip timeout for low vrefresh modes

[Imre Deak]

The current fixed 50 ms timeout for pageflip completion is not long
enough for low vrefresh modes. In general the timeout should account for
one frame for the flip itself + one frame for vblank waiting due to FBC
invalidation + a fixed amount for scheduling overhead delivering the
completion event to userspace. For the usual 60Hz modes the 50 ms
timeout worked ok based on the above (2 * 17 ms + 16 ms), but didn't
work for 30 Hz modes (the minimum timeout for those being ~67 ms).

Based on the above use a timeout length of 2 * mode specific frame
time + 20 ms fixed scheduling delay.

Testcase: igt at kms_flip_tiling
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 tests/intel/kms_flip_tiling.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tests/intel/kms_flip_tiling.c b/tests/intel/kms_flip_tiling.c
index 3bf02564e..e937c2171 100644
--- a/tests/intel/kms_flip_tiling.c
+++ b/tests/intel/kms_flip_tiling.c
@@ -86,6 +86,18 @@ static int try_commit(igt_display_t *display)
 				       COMMIT_ATOMIC : COMMIT_LEGACY);
 }
 
+static uint64_t pageflip_timeout_us(drmModeModeInfo *mode)
+{
+	uint64_t timeout_ns;
+
+	/* 1 frame for flip + 1 frame for vblank wait due to FBC. */
+	timeout_ns = igt_kms_frame_time_from_vrefresh(mode->vrefresh) * 2;
+	/* 20 msec scheduling overhead. */
+	timeout_ns += 20000000;
+
+	return DIV_ROUND_UP(timeout_ns, 1000);
+}
+
 static void
 test_flip_tiling(data_t *data, enum pipe pipe, igt_output_t *output, uint64_t modifier[2])
 {
@@ -137,7 +149,7 @@ test_flip_tiling(data_t *data, enum pipe pipe, igt_output_t *output, uint64_t mo
 	igt_require(ret == 0);
 
 	data->flipevent_in_queue = true;
-	kmstest_wait_for_pageflip(data->drm_fd);
+	kmstest_wait_for_pageflip_timeout(data->drm_fd, pageflip_timeout_us(mode));
 	data->flipevent_in_queue = false;
 
 	/* Get a crc and compare with the reference. */
-- 
2.44.2