Re: [PATCH v2 1/2] drm/i915/guc: Complete all requests of a non-schedulable context

[Javier MV <javiermv@gmail.com>]

On the out-of-order completion in the else branch: that branch keeps the
existing behaviour (only rq is completed, as before this patch). The patch
adds the off-HW case and moves the existing call under the lock.

Leaving rq incomplete there looks right while the context is still enabled
or has a disable in flight. Every path that makes a context non-schedulable
calls guc_context_revoke() right after setting the flag. The schedule
disable that revoke sends, or the one already pending, then completes with
SCHED_STATE_BANNED set, and its done handler cancels the whole list in order.

I'm less sure about the pending enable case. As the review says, the enable
done handler cancels nothing, and revoke has already run by then. So unless
the context runs again, rq would never complete, where today it at least
gets completed. My instrumented runs only logged the off-HW path, so I have
no data on how often either state happens.

If you'd like this handled in this series, I can send a v3 that leaves rq
to the cancel when a disable is pending or the context is enabled, and
keeps the current behaviour for a pending enable.

Javier MV