[Intel-gfx] [PATCH] drm/i915: Check locking in i915_gem_request_unreference

[Daniel Vetter]

On Wed, Nov 26, 2014 at 11:39 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Wed, Nov 26, 2014 at 10:28:13AM +0100, Daniel Vetter wrote:
>> With refcounting it looks like you can just drop that refcount, but
>> that's not really the case. So make sure no one forgets.
>>
>> Motivated by the unlocked call in the mmio flip code.
>
> I had an unlocked variant for exactly this purpose (and a few others
> where we do not want to take the lock again) and so also had the WARN
> inside i915_request_free.
>
> Drop the _gem_, the requests are lower level than GEM itself.

Yeah there's definitely more to do. The one I actually expect you to
scream about is that it keeps an explicit refcount for all the
obj->las_* fences, instead of relying upon the implicit fence that a
correct retire sequence allows us.

This here is just about enforcing correctness.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch