[PATCH v6 2/3] drm/i915/gt: Do not generate the command streamer for all the CCS

[Andi Shyti]

Hi Matt,

On Tue, Mar 26, 2024 at 09:03:10AM -0700, Matt Roper wrote:
> On Wed, Mar 13, 2024 at 09:19:50PM +0100, Andi Shyti wrote:
> > +			/*
> > +			 * Do not create the command streamer for CCS slices
> > +			 * beyond the first. All the workload submitted to the
> > +			 * first engine will be shared among all the slices.
> > +			 *
> > +			 * Once the user will be allowed to customize the CCS
> > +			 * mode, then this check needs to be removed.
> > +			 */
> > +			if (IS_DG2(i915) &&
> > +			    class == COMPUTE_CLASS &&
> > +			    ccs_instance++)
> > +				continue;
> 
> Wouldn't it be more intuitive to drop the non-lowest CCS engines in
> init_engine_mask() since that's the function that's dedicated to
> building the list of engines we'll use?  Then we don't need to kill the
> assertion farther down either.

Because we don't check the result of init_engine_mask() while
creating the engine's structure. We check it only after and
indeed I removed the drm_WARN_ON() check.

I think the whole process of creating the engine's structure in
the intel_engines_init_mmio() can be simplified, but this goes
beyong the scope of the series.

Or am I missing something?

Thanks,
Andi