Re: [Intel-gfx] [PATCH v7 5/9] drm/i915/gt: Enable the CCS_FLUSH bit in the pipe control

[Andrzej Hajda <andrzej.hajda@intel.com>]

On 20.07.2023 23:07, Andi Shyti wrote:
> Enable the CCS_FLUSH bit 13 in the control pipe for render and
> compute engines in platforms starting from Meteor Lake (BSPEC
> 43904 and 47112).
> 
> Fixes: 972282c4cf24 ("drm/i915/gen12: Add aux table invalidate for all engines")
> Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
> Cc: Jonathan Cavitt <jonathan.cavitt@intel.com>
> Cc: Nirmoy Das <nirmoy.das@intel.com>
> Cc: <stable@vger.kernel.org> # v5.8+
> ---
>   drivers/gpu/drm/i915/gt/gen8_engine_cs.c     | 7 +++++++
>   drivers/gpu/drm/i915/gt/intel_gpu_commands.h | 1 +
>   2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> index 7566c89d9def3..9d050b9a19194 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
> @@ -218,6 +218,13 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
>   
>   		bit_group_0 |= PIPE_CONTROL0_HDC_PIPELINE_FLUSH;
>   
> +		/*
> +		 * When required, in MTL+ platforms we need to
> +		 * set the CCS_FLUSH bit in the pipe control
> +		 */
> +		if (GRAPHICS_VER_FULL(rq->i915) >= IP_VER(12, 70))
> +			bit_group_0 |= PIPE_CONTROL_CCS_FLUSH;
> +


Btw, not for this patch, but related: rcs and ccs have slightly 
different set of flushes according to bspec but this functions is the 
same for both. Is it sth we should address, or just safe simplification.

Regards
Andrzej


>   		bit_group_1 |= PIPE_CONTROL_TILE_CACHE_FLUSH;
>   		bit_group_1 |= PIPE_CONTROL_FLUSH_L3;
>   		bit_group_1 |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
> diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> index 5d143e2a8db03..5df7cce23197c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> @@ -299,6 +299,7 @@
>   #define   PIPE_CONTROL_QW_WRITE				(1<<14)
>   #define   PIPE_CONTROL_POST_SYNC_OP_MASK                (3<<14)
>   #define   PIPE_CONTROL_DEPTH_STALL			(1<<13)
> +#define   PIPE_CONTROL_CCS_FLUSH			(1<<13) /* MTL+ */
>   #define   PIPE_CONTROL_WRITE_FLUSH			(1<<12)
>   #define   PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH	(1<<12) /* gen6+ */
>   #define   PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE	(1<<11) /* MBZ on ILK */