Re: [PATCH v2 09/34] drm/xe: Make LRC W/A scratch buffer usage consistent

["Lis, Tomasz" <tomasz.lis@intel.com>]

On 9/24/2025 3:15 AM, Matthew Brost wrote:
> The LRC W/A currently checks for LRC being iomem in some places, while
> in others it checks if the scratch buffer is non-NULL. This
> inconsistency causes issues with the VF post-migration recovery code,
> which blindly passes in a scratch buffer.
>
> This patch standardizes the check by consistently verifying whether the
> LRC is iomem to determine if the scratch buffer should be used.

No need for explicit assert as the kernel will abort by itself if 
state->buffer in NULL, so this is ok.

Reviewed-by: Tomasz Lis <tomasz.lis@intel.com>

-Tomasz

> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_lrc.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
> index 47e9df775072..aed0a3155d1f 100644
> --- a/drivers/gpu/drm/xe/xe_lrc.c
> +++ b/drivers/gpu/drm/xe/xe_lrc.c
> @@ -1248,7 +1248,7 @@ static int setup_bo(struct bo_setup_state *state)
>   
>   static void finish_bo(struct bo_setup_state *state)
>   {
> -	if (!state->buffer)
> +	if (!state->lrc->bo->vmap.is_iomem)
>   		return;
>   
>   	xe_map_memcpy_to(gt_to_xe(state->lrc->gt), &state->lrc->bo->vmap,