[igt-dev] [PATCH i-g-t] [RFC] tests/kms_big_fb: Wait for vblank before collecting CRC

[Mark Yacoub]

On Fri, May 28, 2021 at 12:36 AM Vidya Srinivas
<vidya.srinivas at intel.com> wrote:
>
> Without wait for vblank, CRC mismatch is seen
> between big and small CRC on few Gen11 systems.
>
Tested on ChromeOS on JSL (Drawlat).
Tested-by: Mark Yacoub <markyacoub at chromium.org>
> Signed-off-by: Vidya Srinivas <vidya.srinivas at intel.com>
> ---
>  tests/kms_big_fb.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/tests/kms_big_fb.c b/tests/kms_big_fb.c
> index b35727a09bd0..f90363c3beb2 100644
> --- a/tests/kms_big_fb.c
> +++ b/tests/kms_big_fb.c
> @@ -254,6 +254,7 @@ static void unset_lut(data_t *data)
>  static bool test_plane(data_t *data)
>  {
>         igt_plane_t *plane = data->plane;
> +       igt_display_t *display = &data->display;
>         struct igt_fb *small_fb = &data->small_fb;
>         struct igt_fb *big_fb = &data->big_fb;
>         int w = data->big_fb_width - small_fb->width;
> @@ -337,16 +338,17 @@ static bool test_plane(data_t *data)
>                 igt_display_commit2(&data->display, data->display.is_atomic ?
>                                     COMMIT_ATOMIC : COMMIT_UNIVERSAL);
>
> -
> +               igt_wait_for_vblank(data->drm_fd, display->pipes[data->pipe].crtc_offset);
>                 igt_pipe_crc_collect_crc(data->pipe_crc, &small_crc);
>
>                 igt_plane_set_fb(plane, big_fb);
>                 igt_fb_set_position(big_fb, plane, x, y);
>                 igt_fb_set_size(big_fb, plane, small_fb->width, small_fb->height);
> +
>                 igt_plane_set_size(plane, data->width, data->height);
>                 igt_display_commit2(&data->display, data->display.is_atomic ?
>                                     COMMIT_ATOMIC : COMMIT_UNIVERSAL);
> -
> +               igt_wait_for_vblank(data->drm_fd, display->pipes[data->pipe].crtc_offset);
>                 igt_pipe_crc_collect_crc(data->pipe_crc, &big_crc);
>
>                 igt_plane_set_fb(plane, NULL);
> --
> 2.7.4
>