[Mesa-dev] [PATCH 8/8] panfrost: Add backend targeting the DRM driver

[Kristian Høgsberg]

On Mon, Mar 4, 2019 at 6:11 PM Alyssa Rosenzweig <alyssa at rosenzweig.io> wrote:
>
> > Why aren't we using regular dma-buf fences here? The submit ioctl
> > should be able to take a number of in fences to wait on and return an
> > out fence if requested.
>
> Ah-ha, that sounds like the "proper" approach for mainline. Much of this
> was (incorrectly) inherited from the Arm driver. Thank you for the
> pointer.

I'm not sure - I mean, the submit should take in/out fences, but the
atom mechanism here sounds more like it's for declaring the
dependencies between multiple batches in a renderpass/frame to allow
the kernel to shcedule them? The sync fd may be a little to heavy
handed for that, and if you want to express that kind of dependency to
allow the kernel to reschedule, maybe we need both?