Re: [igt-dev] [PATCH] lib/i915: gem_engine_topology: get eb flags from engine's coordiantes

Chris Wilson
2019-06-20T08:26:54Z

Quoting Tvrtko Ursulin (2019-06-20 09:12:55)
>
> On 20/06/2019 08:52, Andi Shyti wrote:
> > Hi Tvrtko,
> >
> >>> + struct intel_execution_engine2 *e;
> >>> +
> >>> + for_each_context_engine(fd, ctx_id, e)
> >>> + if (class == e->class && instance == e->instance)
> >>> + return e->flags;
> >>
> >> And most important difference, I wouldn't configure the context from this helper. Instead I think all we need is:
> >>
> >> int gem_context_get_eb_flags(int fd, uint32_t ctx, struct i915_engine_class_instance ci)
> >> {

[snip]

> I think it would be wrong to configure the context from this helper. The
> name of the function translates to "give me correct eb.flags for this
> context to submit to this class:instance". All function needs to do is
> to answer this question both on legacy and new kernels.

Yes. I think it would be most surprising if a getter reconfigured the
context.
-Chris