[Intel-gfx] [PATCH 36/36] drm/i915: Support per-context user requests for GPU frequency control

[Chris Wilson]

Quoting Sagar Arun Kamble (2018-03-19 09:51:08)
> 
> 
> On 3/14/2018 3:07 PM, Chris Wilson wrote:
> > @@ -757,8 +767,10 @@ static void guc_submission_tasklet(unsigned long data)
> >   
> >               rq = port_request(&port[0]);
> >       }
> > -     if (!rq)
> > +     if (!rq) {
> >               execlists_clear_active(execlists, EXECLISTS_ACTIVE_USER);
> > +             intel_rps_update_engine(engine, NULL);
> I think we also need to do this (update_engine(NULL)) while handling 
> preemption completion for both GuC and execlists also.
> Doing it as part of execlists_cancel_port_requests will cover all those 
> cases including reset.
> Am I right?

While we don't need it in the intermediate (internal) context switches to
preempt. That is always preceded by execlists_user_end (cancelling the
context frequency selection) or succeeded by the next
execlists_user_begin (selecting the next frequency). However, that was
change was already made to simplify execlists->active handling ;)
-Chris