Re: [PATCH 1/2] drm/i915: Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset

Tvrtko Ursulin
2015-09-30T15:45:42Z

Hi,

On 30/09/15 15:36, Michel Thierry wrote:
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 67ef118..6ca39c1 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -589,11 +589,20 @@ i915_gem_execbuffer_reserve_vma(struct i915_vma *vma,
> if (entry->flags & EXEC_OBJECT_NEEDS_GTT)
> flags |= PIN_GLOBAL;
>
> + /* Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset,
> + * limit address to the first 4GBs for unflagged objects.
> + */
> + flags |= PIN_ZONE_4G;
> + if (entry->flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS)
> + flags &= ~PIN_ZONE_4G;

I spotted this patch purely accidentally since it was probably the
reason pad_to_size IGT started failing in the Android tree - given how
there is mention of changing the allocation order. Anyway beside the point..

Point is when I spotted it by accident, I also spotted this unusual
handling of flags - set then conditionally clear. Why not conditionally
set for one fewer line of code?

Regards,

Tvrtko