Bug 97448

Unfortunate that this tests has been removed from the -dev branch of the CTS.
All I could find was : 

dEQP-VK.api.copy_and_blit.image_to_image.simple_tests.stencil

but this is passing on my machine with Mesa master.

Will look at the CTS's master branch.

I'm using the vulkan-cts-1.0.0 branch.

Thanks,

We are dealing with a test that was previously skipped and is now enabled.

Attached are the expected and actual result of this test.
After a bit of digging I figure that the pitch of the destination surface (R8_UINT W-tiled) has a pitch of 512, the actual picture having a pitch of 256 in linear tiling. It's kind of surprising, and forcing the pitch to 256 fixes the test.

Here is an extract of the driver for pitch computation :

/* From the Broadwell PRM Vol 2d, RENDER_SURFACE_STATE::SurfacePitch:      
 *                                                                         
 *    "If the surface is a stencil buffer (and thus has Tile Mode set      
 *    to TILEMODE_WMAJOR), the pitch must be set to 2x the value           
 *    computed based on width, as the stencil buffer is stored with two    
 *    rows interleaved."                                                   
 *                                                                         
 * This, together with the fact that stencil buffers are referred to as    
 * being Y-tiled in the PRMs for older hardware implies that the           
 * physical size of a W-tile is actually the same as for a Y-tile.         
 */                                                                        

I'm wondering whether we shouldn't double the pitch because as far as I understand meta_copy renders to the buffer as a color attachment. Does this constraint still apply in this case?
Also is this all going away once the blorp work Jason has been working on lands?

Created attachment 125973 [details]
Expected

Created attachment 125974 [details]
Actual

Fixed by :

commit 91987c51e31306bcc52d2c9d18895a533ab08822

anv: meta_blit2d: adapt texel fetch pitch for fake w-tiled
We need to compute detiling coordinates using the physical size of W tiling
(128x32) rather than the logical size (64x64).

v2: Correct comment (Jason)

Fixes dEQP-VK.api.copy_and_blit.image_to_image_stencil

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97448
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>