Re: [PATCH v3 02/15] [media] vb2: add explicit fence user API

From: Gustavo Padovan
Date: Wed Oct 04 2017 - 16:13:01 EST


On Mon, 2017-10-02 at 14:42 +0100, Brian Starkey wrote:
> Hi,
>
> On Thu, Sep 07, 2017 at 03:42:13PM -0300, Gustavo Padovan wrote:
> > From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
> >
> > Turn the reserved2 field into fence_fd that we will use to send
> > an in-fence to the kernel and return an out-fence from the kernel
> > to
> > userspace.
> >
> > Two new flags were added, V4L2_BUF_FLAG_IN_FENCE, that should be
> > used
> > when sending a fence to the kernel to be waited on, and
> > V4L2_BUF_FLAG_OUT_FENCE, to ask the kernel to give back an out-
> > fence.
>
> It seems a bit off to me to add this to the uapi, and document it,
> before any of the implementation is present in the kernel.
>
> Wouldn't it be better to move this patch to be the last one, after
> all
> of the implementation is done?

Yes, that seems a better idea.

Gustavo