[PATCH 2/3] dma-buf/sync_file: add sync_file_get_fence()

[Gustavo Padovan]

2016-06-10 Chris Wilson <chris at chris-wilson.co.uk>:

> On Thu, Jun 09, 2016 at 12:05:29PM -0300, Gustavo Padovan wrote:
> > From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> > 
> > Creates a function that given an sync file descriptor returns a
> > fence_collection containing all fences in the sync_file.
> > 
> > If there is only one fence in the sync_file this fence itself is returned,
> > however if there is more than one, a fence_collection fence is returned.
> > 
> > v2: Comments by Daniel Vetter
> > 	- Adapt to new version of fence_collection_init()
> > 	- Hold a reference for the fence we return
> > 
> > v3:     - Adapt to use fput() directly
> > 	- rename to sync_file_get_fence() as we always return one fence
> > 
> > v4: Adapt to use fence_array
> 
> The sync_file looks just like a fence_array plus struct file integration.
> Is there a good reason why we cannot just use fence_array here?

I think the only reason is because I haven't thought about this before.
If we add proper support to fence_array we can make sync_files even
simpler.

	Gustavo