Re: [Intel-gfx] [PATCH] drm/i915: consider HAS_FLAT_CCS() in needs_ccs_pages

["Das, Nirmoy" <nirmoy.das@intel.com>]

LGTM Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>

On 9/5/2022 12:53 PM, Matthew Auld wrote:
> Just move the HAS_FLAT_CCS() check into needs_ccs_pages. This also then
> fixes i915_ttm_memcpy_allowed() which was incorrectly reporting true on
> DG1, even though it doesn't have small-BAR or flat-CCS.
>
> References: https://gitlab.freedesktop.org/drm/intel/-/issues/6605
> Fixes: efeb3caf4341 ("drm/i915/ttm: disallow CPU fallback mode for ccs pages")
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Nirmoy Das <nirmoy.das@intel.com>
> ---
>   drivers/gpu/drm/i915/gem/i915_gem_object.c | 3 +++
>   drivers/gpu/drm/i915/gem/i915_gem_ttm.c    | 2 +-
>   2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
> index 389e9f157ca5..85482a04d158 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
> @@ -723,6 +723,9 @@ bool i915_gem_object_needs_ccs_pages(struct drm_i915_gem_object *obj)
>   	bool lmem_placement = false;
>   	int i;
>   
> +	if (!HAS_FLAT_CCS(to_i915(obj->base.dev)))
> +		return false;
> +
>   	for (i = 0; i < obj->mm.n_placements; i++) {
>   		/* Compression is not allowed for the objects with smem placement */
>   		if (obj->mm.placements[i]->type == INTEL_MEMORY_SYSTEM)
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> index bc9c432edffe..f64a3deb12fc 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> @@ -297,7 +297,7 @@ static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo,
>   		i915_tt->is_shmem = true;
>   	}
>   
> -	if (HAS_FLAT_CCS(i915) && i915_gem_object_needs_ccs_pages(obj))
> +	if (i915_gem_object_needs_ccs_pages(obj))
>   		ccs_pages = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size,
>   						      NUM_BYTES_PER_CCS_BYTE),
>   					 PAGE_SIZE);