[igt-dev] [PATCH i-g-t] tests/kms_atomic_transition: Don't abuse the HSKEW flag to force a modeset

[Maarten Lankhorst]

Op 30-01-18 om 16:49 schreef Ville Syrjala:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Since kernel commit e995ca0b8139 ("drm/i915: Provide a device level
> .mode_valid() hook") i915 will bluntly reject the HSKEW mode flag. Thus
> we can't abuse it to force a modeset.
>
> Since we don't particularly care about the visual results here we can
> risk making the display unhappy by eg. flipping the hsync polarity
> instead.
Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Also add a comment documenting why we're doing this.
>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104848
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  tests/kms_atomic_transition.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tests/kms_atomic_transition.c b/tests/kms_atomic_transition.c
> index 798639393421..aa9a6f8439ea 100644
> --- a/tests/kms_atomic_transition.c
> +++ b/tests/kms_atomic_transition.c
> @@ -410,7 +410,8 @@ run_transition_test(igt_display_t *display, enum pipe pipe, igt_output_t *output
>  
>  	mode = igt_output_get_mode(output);
>  	override_mode = *mode;
> -	override_mode.flags |= DRM_MODE_FLAG_HSKEW;
> +	/* try to force a modeset */
> +	override_mode.flags ^= DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NHSYNC;
>  
>  	igt_create_fb(display->drm_fd, mode->hdisplay, mode->vdisplay,
>  		      DRM_FORMAT_XRGB8888, LOCAL_DRM_FORMAT_MOD_NONE, &fb);