[igt-dev] [PATCH i-g-t 5/5] tests/kms_setmode: Validate the vbl sequence numbers

[Chris Wilson]

Quoting Ville Syrjala (2019-03-07 21:39:26)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Make sure we haven't already passed the seq numbers we're
> requesting when doing the ts calibration.
> 
> Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  tests/kms_setmode.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/tests/kms_setmode.c b/tests/kms_setmode.c
> index acd606cd5b5e..5ce1397f968f 100644
> --- a/tests/kms_setmode.c
> +++ b/tests/kms_setmode.c
> @@ -447,8 +447,17 @@ static void check_timings(int crtc_idx, const drmModeModeInfo *kmode)
>         wait.request.type |= DRM_VBLANK_ABSOLUTE | DRM_VBLANK_EVENT;
>         wait.request.sequence = last_seq;
>         for (n = 0; n < CALIBRATE_TS_STEPS; n++) {
> +               drmVBlank check = {};
> +
>                 ++wait.request.sequence;
>                 do_or_die(drmWaitVBlank(drm_fd, &wait));
> +
> +               /* Double check that haven't already missed the vblank */
> +               check.request.type = kmstest_get_vbl_flag(crtc_idx);
> +               check.request.type |= DRM_VBLANK_RELATIVE;
> +               do_or_die(drmWaitVBlank(drm_fd, &check));

I'm thinking this reinforces the NEXTONMISS alignment as opposed to
making that argument moot :)
-Chris