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

[Sharma, Swati2]

Hi Imre,

Do we have some gitlab issue associated with this fix?

On 22-10-2024 09:23 pm, Imre Deak wrote:
> 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. */