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

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.