Re: [PATCH v2 07/11] drm/xe/xe2hpg: Remove extra allocation of CCS pages for dgfx

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 08-04-2024 21:59, Balasubramani Vivekanandan wrote:
> From: Akshata Jahagirdar <akshata.jahagirdar@intel.com>
>
> On Xe2 dGPU, compression is only supported with VRAM. When copying from
> VRAM -> system memory the KMD uses mapping with uncompressed PAT
> so the copy in system memory is guaranteed to be uncompressed.
> When restoring such buffers from system memory -> VRAM the KMD can't
> easily know which pages were originally compressed, so we always use
> uncompressed -> uncompressed here.
> so this means that there's no need for extra CCS storage on such
> platforms.
>
> v2: More description added to commit message
>
> Signed-off-by: Akshata Jahagirdar <akshata.jahagirdar@intel.com>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_bo.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 6166bc715656..fdeb3691d3f6 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -2201,6 +2201,9 @@ bool xe_bo_needs_ccs_pages(struct xe_bo *bo)
>   {
>   	struct xe_device *xe = xe_bo_device(bo);
>   
> +	if (GRAPHICS_VER(xe) >= 20 && IS_DGFX(xe))
> +		return false;
> +

LGTM.

Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

>   	if (!xe_device_has_flat_ccs(xe) || bo->ttm.type != ttm_bo_type_device)
>   		return false;
>