2018-01-15 Alexandre Courbot <acourbot@xxxxxxxxxxxx>: > On Thu, Jan 11, 2018 at 1:07 AM, Gustavo Padovan <gustavo@xxxxxxxxxxx> wrote: > > From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx> > > > > Explicit synchronization benefits a lot from ordered queues, they fit > > better in a pipeline with DRM for example so create a opt-in way for > > drivers notify videobuf2 that the queue is unordered. > > > > Drivers don't need implement it if the queue is ordered. > > This is going to make user-space believe that *all* vb2 drivers use > ordered queues by default, at least until non-ordered drivers catch up > with this change. Wouldn't it be less dangerous to do the opposite > (make queues non-ordered by default)? The rational behind this decision was because most formats/drivers are ordered so only a small amount of drivers need to changed. I think this was proposed by Hans on the Media Summit. I understand your concern. My question is how dangerous will it be. If you are building a product you will make the changes in the driver if they are not there yet, or if it is a distribution you'd never know which driver/format you are using so you should be prepared for everything. AFAIK all Capture drivers are ordered and that is where I think fences is most useful. Gustavo
