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.
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
