On Mon, Jul 17, 2023 at 10:54:37AM -0700, Matt Roper wrote:
> On Mon, Jul 17, 2023 at 07:30:55PM +0200, Andi Shyti wrote:
> > From: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
> >
> > All memory traffic must be quiesced before requesting
> > an aux invalidation on platforms that use Aux CCS.
> >
> > Fixes: 972282c4cf24 ("drm/i915/gen12: Add aux table invalidate for all engines")
> > Signed-off-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
> > Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx> # v5.8+
> > ---
> > drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> > index 563efee055602..bee3b7dc595cf 100644
> > --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> > +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> > @@ -202,6 +202,13 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
> > {
> > struct intel_engine_cs *engine = rq->engine;
> >
> > + /*
> > + * Aux invalidations on Aux CCS platforms require
> > + * memory traffic is quiesced prior.
> > + */
> > + if ((mode & EMIT_INVALIDATE) && !HAS_FLAT_CCS(engine->i915))
>
> It's a pre-existing mistake in drm-tip at the moment, but we shouldn't
> assume !flatccs always implies auxccs. PVC has neither, and there may
> be other similar platforms in the future. We should probably add a
> helper function for AuxCCS, similar to what we added to the Xe driver
> recently:
>
> https://patchwork.freedesktop.org/patch/539304/?series=118334&rev=1
>
BTW, since this patch didn't handle it I was expecting to see another
patch in the series that quiesces memory for the non-RCS/CCS engines,
but it looks like there isn't one yet. So we should probably add the
necessary MI_FLUSH_DW logic for the other engines to this patch as well.
Matt
>
> Matt
>
>
> > + mode |= EMIT_FLUSH;
> > +
> > if (mode & EMIT_FLUSH) {
> > u32 flags = 0;
> > int err;
> > --
> > 2.40.1
> >
>
> --
> Matt Roper
> Graphics Software Engineer
> Linux GPU Platform Enablement
> Intel Corporation
--
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation
