[igt-dev] [PATCH i-g-t] i915/gem_mocs_settings/mocs-isolation: Filter out missing rings

[Chris Wilson]

Quoting Kumar Valsan, Prathap (2019-03-20 16:40:50)
> On Tue, Mar 19, 2019 at 07:23:20PM +0000, Chris Wilson wrote:
> > Don't try to evaluate whether reads executed on an absent ring do
> > anything.
> 
> Chris,
> 
> I am trying to understand this patch and has this question.
> AFAIK every GPU engine has an assosiated ring buffer per
> context. Absent ring is a error case?

Not all HW has the same set of engines available. And we should get a
failure from gem_execbuf() if you try to dispatch something on a ring
that didn't exist. What I haven't actually answered is why we actually
hit a failure later. But it's definitely a requirement of the test that
the engine exist.
-Chris