[igt-dev] [PATCH i-g-t v23 22/37] tests/api_intel_bb: Add subtest to check render batch on the last page

[Daniel Vetter]

On Mon, Mar 15, 2021 at 05:58:27PM +0100, Zbigniew Kempczyński wrote:
> Last page (on 48-bit ppgtt) seems to be problematic when full
> 3D pipeline batch is inserted and executed from it. Try to find out
> which generations are still prone to hang on it.
> 
> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>

Discussed this a bit on irc, and this results in failures. I think it's
good to have this as a test going forward to make sure hw doesn't break in
bad ways, but merging a test that's red for old platforms isn't a good
pattern. It's imo part of the reason our CI results look so horrible.

So options:
- drop this patch
- limit the test to only run on modern platforms that don't suck, with a
  comment explaining where it's broken

And I guess need to retract my hurried ack on this patch too :-)
-Daniel

> ---
>  tests/i915/api_intel_bb.c | 75 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/tests/i915/api_intel_bb.c b/tests/i915/api_intel_bb.c
> index 29d4dd7b6..7f56c1cbc 100644
> --- a/tests/i915/api_intel_bb.c
> +++ b/tests/i915/api_intel_bb.c
> @@ -36,6 +36,7 @@
>  #include <glib.h>
>  #include <zlib.h>
>  #include "intel_bufops.h"
> +#include "sw_sync.h"
>  
>  #define PAGE_SIZE 4096
>  
> @@ -1320,6 +1321,77 @@ static void render_ccs(struct buf_ops *bops)
>  	igt_assert_f(fails == 0, "render-ccs fails: %d\n", fails);
>  }
>  
> +static void last_page(struct buf_ops *bops, uint32_t width, uint32_t height)
> +{
> +	struct intel_bb *ibb1, *ibb2;
> +	struct intel_buf src, dst;
> +	int i915 = buf_ops_get_fd(bops);
> +	uint32_t devid = intel_get_drm_devid(i915);
> +	igt_render_copyfunc_t render_copy = NULL;
> +	uint64_t gtt_size;
> +	uint64_t ctx;
> +	int ret;
> +
> +	igt_require(gem_uses_full_ppgtt(i915));
> +	gtt_size = gem_aperture_size(i915);
> +
> +	ctx = gem_context_create(i915);
> +
> +	ibb1 = intel_bb_create_full(i915, ctx, PAGE_SIZE,
> +				   0, gtt_size, INTEL_ALLOCATOR_SIMPLE,
> +				   ALLOC_STRATEGY_LOW_TO_HIGH);
> +
> +	ibb2 = intel_bb_create_full(i915, 0, PAGE_SIZE,
> +				   0, gtt_size, INTEL_ALLOCATOR_SIMPLE,
> +				   ALLOC_STRATEGY_HIGH_TO_LOW);
> +
> +	if (debug_bb) {
> +		intel_bb_set_debug(ibb1, true);
> +		intel_bb_set_debug(ibb2, true);
> +	}
> +
> +	scratch_buf_init(bops, &src, width, height, I915_TILING_NONE,
> +			 I915_COMPRESSION_NONE);
> +	scratch_buf_init(bops, &dst, width, height, I915_TILING_NONE,
> +			 I915_COMPRESSION_NONE);
> +	scratch_buf_draw_pattern(bops, &src,
> +				 0, 0, width, height,
> +				 0, 0, width, height, 0);
> +
> +	render_copy = igt_get_render_copyfunc(devid);
> +	igt_assert(render_copy);
> +
> +	render_copy(ibb1,
> +		    &src,
> +		    0, 0, width, height,
> +		    &dst,
> +		    0, 0);
> +	gem_sync(i915, dst.handle);
> +	sync_fence_wait(ibb1->fence, -1);
> +	igt_assert_eq(sync_fence_status(ibb1->fence), 1);
> +	intel_bb_destroy(ibb1);
> +
> +	intel_buf_close(bops, &dst);
> +	scratch_buf_init(bops, &dst, width, height, I915_TILING_NONE,
> +			 I915_COMPRESSION_NONE);
> +
> +	render_copy(ibb2,
> +		    &src,
> +		    0, 0, width, height,
> +		    &dst,
> +		    0, 0);
> +
> +	/* We likely got a hang here, so free resources before assert */
> +	sync_fence_wait(ibb2->fence, -1);
> +	ret = sync_fence_status(ibb2->fence);
> +
> +	intel_bb_destroy(ibb2);
> +	intel_buf_close(bops, &src);
> +	intel_buf_close(bops, &dst);
> +
> +	igt_assert_f(ret == 1, "Batch in last page in rcs leads to hang\n");
> +}
> +
>  static int opt_handler(int opt, int opt_index, void *data)
>  {
>  	switch (opt) {
> @@ -1471,6 +1543,9 @@ igt_main_args("dpib", NULL, help_str, opt_handler, NULL)
>  	igt_subtest("render-ccs")
>  		render_ccs(bops);
>  
> +	igt_subtest("last-page")
> +		last_page(bops, 512, 512);
> +
>  	igt_fixture {
>  		buf_ops_destroy(bops);
>  		close(i915);
> -- 
> 2.26.0
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch