[PATCH v2 01/12] drm/panfrost: Make sure MMU context lifetime is not bound to panfrost_priv

[Alyssa Rosenzweig]

> Jobs can be in-flight when the file descriptor is closed (either because
> the process did not terminate properly, or because it didn't wait for
> all GPU jobs to be finished), and apparently panfrost_job_close() does
> not cancel already running jobs. Let's refcount the MMU context object
> so it's lifetime is no longer bound to the FD lifetime and running jobs
> can finish properly without generating spurious page faults.

Remind me - why can't we hard stop in-flight jobs when the fd is closed?
I've seen cases where kill -9'ing a badly behaved process doesn't end
the fault storm, or unfreeze the desktop.