[RFC PATCH 0/7] drm/panfrost: Add a new submit ioctl

[Alyssa Rosenzweig]

> I'm not familiar with panfrost's needs and I don't work on a tiler and
> I know there are different issues there.  But...

The primary issue is we submit vertex+compute and fragment for each
batch as two disjoint jobs (with a dependency of course), reflecting the
internal hardware structure as parallel job slots. That we actually
require two ioctls() and a roundtrip for this is a design wart inherited
from early days of the kernel driver. The downstream Mali driver handles
this by allowing multiple jobs to be submitted with a single ioctl, as
Boris's patch enables. In every other respect I believe our needs are
similar to other renderonly drivers. (What does turnip do?)