[igt-dev] [PATCH i-g-t v1 3/3] igt/tests: Tolerate if kernel can't have all planes

[Daniel Vetter]

On Fri, Mar 29, 2019 at 01:29:01PM +0200, Stanislav Lisovskiy wrote:
> With some upcoming changes i915 might not allow
> all sprite planes enabled, depending on available
> bandwidth limitation. Thus the test need to decrement
> amount of planes and try again, instead of panicking.
> 
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>

I'm looking at a similar problem in kms_concurrent, and I think we now
also need to randomize the planes we pick. With bw limits (and other stuff
really, this is just the one we're hitting now) we'd otherwise have a good
chance of not testing the last few planes. By randomizing which planes
we're picking we should be able to make things a lot more interesting for
the kernel.
-Daniel

> ---
>  tests/kms_atomic_transition.c | 25 ++++++++++++++++++-------
>  1 file changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/tests/kms_atomic_transition.c b/tests/kms_atomic_transition.c
> index ed271532..657a7d1c 100644
> --- a/tests/kms_atomic_transition.c
> +++ b/tests/kms_atomic_transition.c
> @@ -215,6 +215,7 @@ static void setup_parms(igt_display_t *display, enum pipe pipe,
>  	uint32_t n_overlays;
>  	igt_plane_t *plane;
>  	uint32_t iter_mask;
> +	int retries = n_planes - 1;
>  
>  	do_or_die(drmGetCap(display->drm_fd, DRM_CAP_CURSOR_WIDTH, &cursor_width));
>  	if (cursor_width >= mode->hdisplay)
> @@ -224,6 +225,7 @@ static void setup_parms(igt_display_t *display, enum pipe pipe,
>  	if (cursor_height >= mode->vdisplay)
>  		cursor_height = mode->vdisplay;
>  
> +retry:
>  	n_overlays = 0;
>  	iter_mask = 0;
>  
> @@ -266,7 +268,6 @@ static void setup_parms(igt_display_t *display, enum pipe pipe,
>  	 * Pre gen9 not all sizes are supported, find the biggest possible
>  	 * size that can be enabled on all sprite planes.
>  	 */
> -retry:
>  	prev_w = sprite_width = cursor_width;
>  	prev_h = sprite_height = cursor_height;
>  
> @@ -286,12 +287,22 @@ retry:
>  		if (is_atomic_check_plane_size_errno(ret)) {
>  			if (cursor_width == sprite_width &&
>  			    cursor_height == sprite_height) {
> -				igt_assert_f(alpha,
> -					      "Cannot configure the test with all sprite planes enabled\n");
> -
> -				/* retry once with XRGB format. */
> -				alpha = false;
> -				goto retry;
> +				if (--retries >= 0) {
> +					/* retry once with XRGB format. */
> +					if (alpha) {
> +						alpha = false;
> +					}
> +					else if (display->pipes[pipe].n_planes > 0) {
> +						display->pipes[pipe].n_planes--;
> +						igt_info("Reduced available planes to %d\n",
> +							    display->pipes[pipe].n_planes);
> +					}
> +					n_planes = display->pipes[pipe].n_planes;
> +					igt_assert_f(n_planes > 0, "No planes left to proceed with!");
> +					goto retry;
> +				}
> +				igt_assert_f(retries > 0,
> +				      "Cannot configure the test with all sprite planes enabled\n");
>  			}
>  
>  			sprite_width = prev_w;
> -- 
> 2.17.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch