Hi Matt,
On Thu, Feb 15, 2024 at 08:55:41AM -0800, Matt Roper wrote:
> On Thu, Feb 15, 2024 at 02:59:23PM +0100, Andi Shyti wrote:
> > The hardware should not dynamically balance the load between CCS
> > engines. Wa_16016805146 recommends disabling it across all
>
> Is this the right workaround number? When I check the database, this
> workaround was rejected on both DG2-G10 and DG2-G11, and doesn't even
> have an entry for DG2-G12.
>
> There are other workarounds that sound somewhat related to load
> balancing (e.g., part 3 of Wa_14019159160), but what's asked there is
> more involved than just setting one register bit and conflicts a bit
> with the second patch of this series.
thanks for checking it. Indeed the WA I mentioned is limited to
a specific platform. This recommendation comes in different WA,
e.g. this one: Wa_14019186972 (3rd point). Will start using that
as a reference.
Thank you.
Andi
>
>
> Matt
>
> > platforms.
> >
> > Fixes: d2eae8e98d59 ("drm/i915/dg2: Drop force_probe requirement")
> > Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> > Cc: Chris Wilson <chris.p.wilson@xxxxxxxxxxxxxxx>
> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> > Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx> # v6.2+
> > ---
> > drivers/gpu/drm/i915/gt/intel_gt_regs.h | 1 +
> > drivers/gpu/drm/i915/gt/intel_workarounds.c | 6 ++++++
> > 2 files changed, 7 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> > index 50962cfd1353..cf709f6c05ae 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> > @@ -1478,6 +1478,7 @@
> >
> > #define GEN12_RCU_MODE _MMIO(0x14800)
> > #define GEN12_RCU_MODE_CCS_ENABLE REG_BIT(0)
> > +#define XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE REG_BIT(1)
> >
> > #define CHV_FUSE_GT _MMIO(VLV_GUNIT_BASE + 0x2168)
> > #define CHV_FGT_DISABLE_SS0 (1 << 10)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > index d67d44611c28..7f42c8015f71 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > @@ -2988,6 +2988,12 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
> > wa_mcr_masked_en(wal, GEN8_HALF_SLICE_CHICKEN1,
> > GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE);
> > }
> > +
> > + /*
> > + * Wa_16016805146: disable the CCS load balancing
> > + * indiscriminately for all the platforms
> > + */
> > + wa_masked_en(wal, GEN12_RCU_MODE, XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE);
> > }
> >
> > static void
> > --
> > 2.43.0
> >
>
> --
> Matt Roper
> Graphics Software Engineer
> Linux GPU Platform Enablement
> Intel Corporation
