[Intel-gfx] [PATCH 4/5] drm/i915/guc: stop calling execlists_set_default_submission

[Chris Wilson]

Quoting Daniele Ceraolo Spurio (2021-01-06 02:38:09)
> 
> 
> On 1/5/2021 5:02 PM, Chris Wilson wrote:
> > Quoting Daniele Ceraolo Spurio (2021-01-05 23:19:46)
> >> Initialize all required entries from guc_set_default_submission, instead
> >> of calling the execlists function. The previously inherited setup has
> >> been copied over from the execlist code and simplified by removing the
> >> execlists submission-specific parts.
> >>
> >> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> >> Cc: Matthew Brost <matthew.brost at intel.com>
> >> Cc: John Harrison <john.c.harrison at intel.com>
> >> ---
> >> +       if (INTEL_GEN(engine->i915) >= 12)
> >> +               engine->flags |= I915_ENGINE_HAS_RELATIVE_MMIO;
> > We should probably lift this to intel_engine_setup().
> 
> GuC requires a more extensive usage of the relative mmio stuff, given 
> that it picks which engine to submit to when using virtual engines, so 
> I'm not sure if the support is going to look exactly the same for both 
> back-ends. There is an old patch from John H to rework the relative mmio 
> (https://patchwork.freedesktop.org/patch/332558/), which will have to 
> land in some form as part of the GuC submission re-enabling. I'd prefer 
> to wait for that to land before moving this flag.

Whether or not LR* take the flag is independent of the submission
backend. As to when to use the flag, I think that patch needs a lot more
refinement.

I915_ENGINE_HAS_RELATIVE_MMIO is the odd-one-out in the flags atm as it
reflects HW capability.
-Chris