[Intel-gfx] [PATCH 2/2] drm/i915: Bump pin_count to UINT_MAX.

[Maarten Lankhorst]

Op 23-05-16 om 16:25 schreef Chris Wilson:
> On Mon, May 23, 2016 at 03:37:41PM +0200, Maarten Lankhorst wrote:
>> With nonblocking unpin there can be many cursor pins before they're
>> cleared by the next page flip.
>>
>> Fix this by extending pin_count to the full 32-bit to prevent a
>> WARN_ON(vma->pin_count == DRM_I915_GEM_OBJECT_MAX_PIN_COUNT)
> This is a hack that affects non-KMS paths. Being able to process binding
> in a single operation on all architectures is something we want to
> preserve.
>
> Why is every cursor movement generating an unpin work? Should I just
> start poking registers from userspace to avoid a silly kerenl?
> -Chris
>
All the unpin work gets batched till after the next vblank, it's not very efficient
but if you want to fix it you should just add the vma to plane state already.

According to Ville unpin count would still be too low on BXT/SKL, so it wouldn't
remove the need for this patch anyway..