[Mesa-dev] [PATCH 1/8] i965/drm: Make brw_bo_alloc_tiled take tiling by value, not pointer.

[Chris Wilson]

On Tue, Apr 11, 2017 at 09:02:44AM -0700, Kenneth Graunke wrote:
> For some reason we passed tiling by pointer, through several layers,
> even though the functions only read the initial value, and never
> actually change it.  We even had a do-while loop that executed until
> the tiling mode matched - except it always did, so it only ran once.
> We then had bogus error handling in case it changed the tiling mode
> to something nonsensical...which it never did.

I don't know why either. Using the blitter, there's some value in using
tighter very small buffers (where a tiled buffer actually increases the
TLB pressure) but you always need an explicitly tiled surface to make
the render pipeline happy. And besides, you want to dictate the tiling
mode from the surface selection and not have the lowlevel buffer
allocation code second guess.
 
> Drop all this nonsense.
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre