[Intel-gfx] [PATCH 18/18] drm/i915: Support explicit fencing for execbuf

[John Harrison]

On 30/08/2016 09:18, Chris Wilson wrote:
> Now that the user can opt-out of implicit fencing, we need to give them
> back control over the fencing. We employ sync_file to wrap our
> drm_i915_gem_request and provide an fd that userspace can merge with
> other sync_file fds and pass back to the kernel to wait upon before
> future execution.

> +			args->rsvd2 &= ~((u64)0xffffffff << 32);
> +			args->rsvd2 |= (u64)out_fence_fd << 32;
>
I didn't see a response to the suggestion of renaming rsvd2 to something 
more useful or even replacing it with a pair of u32 values instead. At 
the very least, I think it is worth adding a comment to the structure 
declaration to say that the field is actually in use for something now.