The EU limit of 128 GRFs should allow 32 vertex elements of 4 GRFs.
However, the maximum allowed value of "Vertex URB Entry Read Length"
in SIMD8 is 15. And 15 * 8 = 120 gives us a limit of 30 vertex elements.
Because we also need to reserve a vertex buffer to upload
VertexIndex/InstanceIndex and another to upload DrawID when needed,
we can only expose 28.
Cc: "17.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
(cherry picked from commit
31f1863ace73d31a579e5c36252a957818ad09cf)
*/
#define ANV_HZ_FC_VAL 1.0f
-#define MAX_VBS 31
+#define MAX_VBS 28
#define MAX_SETS 8
#define MAX_RTS 8
#define MAX_VIEWPORTS 16