Re: [RFC v5 08/11] [media] vb2: add videobuf2 dma-buf fence helpers

From: Alexandre Courbot
Date: Fri Nov 17 2017 - 02:11:32 EST

On Friday, November 17, 2017 4:02:56 PM JST, Alexandre Courbot wrote:
On Thursday, November 16, 2017 2:10:54 AM JST, Gustavo Padovan wrote:
From: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>

Add a videobuf2-fence.h header file that contains different helpers
for DMA buffer sharing explicit fence support in videobuf2.

v2: - use fence context provided by the caller in vb2_fence_alloc()

Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> ...

It is probably not a good idea to define that struct here since it will be
deduplicated for every source file that includes it.

Maybe change it to a simple declaration, and move the definition to
videobuf2-core.c or a dedicated videobuf2-fence.c file?

+static inline struct dma_fence *vb2_fence_alloc(u64 context)
+ struct dma_fence *vb2_fence = kzalloc(sizeof(*vb2_fence), GFP_KERNEL);
+ ...

Not sure we gain a lot by having this function static inline, but your call.

Looking at the following patch, since it seems that this function is only to be
called from vb2_setup_out_fence() anyway, you may as well make it static in
videobuf2-core.c or even inline it in vb2_setup_out_fence() - it would only
add a few extra lines to this function.