[Intel-gfx] [PATCH 5/7] drm/i915: Interrupt driven fences

[Chris Wilson]

On Fri, Jan 08, 2016 at 06:47:26PM +0000, John.C.Harrison at Intel.com wrote:
> From: John Harrison <John.C.Harrison at Intel.com>
> 
> The intended usage model for struct fence is that the signalled status
> should be set on demand rather than polled. That is, there should not
> be a need for a 'signaled' function to be called everytime the status
> is queried. Instead, 'something' should be done to enable a signal
> callback from the hardware which will update the state directly. In
> the case of requests, this is the seqno update interrupt. The idea is
> that this callback will only be enabled on demand when something
> actually tries to wait on the fence.

But struct fence already has support for that model, i.e.
fence_add_callback(). This looks to duplicate that code.

What exactly are you trying to improve?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre