[igt-dev] [PATCH i-g-t 02/17] igt/gem_tiled_partial_pwrite_pread: Check for known swizzling

[Tvrtko Ursulin]

On 02/07/2018 10:07, Chris Wilson wrote:
> As we want to compare a templated tiling pattern against the target_bo,
> we need to know that the swizzling is compatible. Or else the two
> tiling pattern may differ due to underlying page address that we cannot
> know, and so the test may sporadically fail.
> 
> References: https://bugs.freedesktop.org/show_bug.cgi?id=102575
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   tests/gem_tiled_partial_pwrite_pread.c | 24 ++++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
> 
> diff --git a/tests/gem_tiled_partial_pwrite_pread.c b/tests/gem_tiled_partial_pwrite_pread.c
> index fe573c37c..83c57c07d 100644
> --- a/tests/gem_tiled_partial_pwrite_pread.c
> +++ b/tests/gem_tiled_partial_pwrite_pread.c
> @@ -249,6 +249,24 @@ static void test_partial_read_writes(void)
>   	}
>   }
>   
> +static bool known_swizzling(uint32_t handle)
> +{
> +	struct drm_i915_gem_get_tiling2 {
> +		uint32_t handle;
> +		uint32_t tiling_mode;
> +		uint32_t swizzle_mode;
> +		uint32_t phys_swizzle_mode;
> +	} arg = {
> +		.handle = handle,
> +	};
> +#define DRM_IOCTL_I915_GEM_GET_TILING2	DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_GET_TILING, struct 

Can't we rely on this being in system headers by now?

drm_i915_gem_get_tiling2)
> +
> +	if (igt_ioctl(fd, DRM_IOCTL_I915_GEM_GET_TILING2, &arg))
> +		return false;
> +
> +	return arg.phys_swizzle_mode == arg.swizzle_mode;
> +}
> +
>   igt_main
>   {
>   	uint32_t tiling_mode = I915_TILING_X;
> @@ -271,6 +289,12 @@ igt_main
>   						      &tiling_mode, &scratch_pitch, 0);
>   		igt_assert(tiling_mode == I915_TILING_X);
>   		igt_assert(scratch_pitch == 4096);
> +
> +		/*
> +		 * As we want to compare our template tiled pattern against
> +		 * the target bo, we need consistent swizzling on both.
> +		 */
> +		igt_require(known_swizzling(scratch_bo->handle));
>   		staging_bo = drm_intel_bo_alloc(bufmgr, "staging bo", BO_SIZE, 4096);
>   		tiled_staging_bo = drm_intel_bo_alloc_tiled(bufmgr, "scratch bo", 1024,
>   							    BO_SIZE/4096, 4,
> 

Another option could be to keep allocating until we found one in the 
memory area with compatible swizzling? Like this it may be some noise in 
the test pass<->skip transitions.

Regards,

Tvrtko