Re: [RFC 1/6] drm/fence: add FENCE_FD property to planes

From: Rob Clark
Date: Tue Apr 05 2016 - 11:23:10 EST


On Tue, Apr 5, 2016 at 10:19 AM, Daniel Stone <daniel@xxxxxxxxxxxxx> wrote:
>
>> hmm, I'm assuming that the in/out arrays are handled in
>> drm_mode_atomic_ioctl() and the drivers never see 'em..
>
> True, but it complicates the (already not hugely straightforward)
> parsing that the ioctl has to do. It also makes extending the ioctl a
> little harder to do in future, because you're adding in two
> variable-size elements, and have to do some fairly complicated parsing
> to even figure out what the size _should_ be. So I'd rather not do it
> if there was any way out of it; at the very least it'd have to be
> userptr rather than array.


oh, I was assuming ptr to a user array (rather than var length ioctl
struct) for both in and out fences. I guess my wording didn't make
that clear. But yeah, it would be madness to do anything else.

BR,
-R