[PATCH 1/1] drm/xe: Fix NPD in ggtt_node_remove()

[Upadhyay, Tejas]

> -----Original Message-----
> From: Ghimiray, Himal Prasad <himal.prasad.ghimiray at intel.com>
> Sent: Wednesday, August 28, 2024 2:25 PM
> To: intel-xe at lists.freedesktop.org
> Cc: Ghimiray, Himal Prasad <himal.prasad.ghimiray at intel.com>; Vivi, Rodrigo
> <rodrigo.vivi at intel.com>; De Marchi, Lucas <lucas.demarchi at intel.com>;
> Upadhyay, Tejas <tejas.upadhyay at intel.com>
> Subject: [PATCH 1/1] drm/xe: Fix NPD in ggtt_node_remove()
> 
> Make sure that ggtt_node_remove() is invoked only if both node and ggtt are
> not null. Move the null checks to the caller function xe_ggtt_node_remove().
> 
> Fixes: 919bb54e989c ("drm/xe: Fix missing runtime outer protection for
> ggtt_remove_node")
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Cc: Tejas Upadhyay <tejas.upadhyay at intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_ggtt.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
> index 86fc6afa43bd..2fa8a22ebbf9 100644
> --- a/drivers/gpu/drm/xe/xe_ggtt.c
> +++ b/drivers/gpu/drm/xe/xe_ggtt.c
> @@ -286,9 +286,6 @@ static void ggtt_node_remove(struct xe_ggtt_node
> *node)
>  	bool bound;
>  	int idx;
> 
> -	if (!node || !node->ggtt)
> -		return;
> -
>  	bound = drm_dev_enter(&xe->drm, &idx);
> 
>  	mutex_lock(&ggtt->lock);
> @@ -328,6 +325,9 @@ static void ggtt_node_remove_work_func(struct
> work_struct *work)
>   */
>  void xe_ggtt_node_remove(struct xe_ggtt_node *node, bool invalidate)  {
> +	if (!node || !node->ggtt)
> +		return;
> +

I think better to declare and assign after NULL check. Something like below,
struct xe_ggtt *ggtt;
struct xe_device *xe;
....
....
if (!node || !node->ggtt)
         return;
ggtt = node->ggtt;
xe = tile_to_xe(ggtt->tile);

Thanks,
Tejas
>  	struct xe_ggtt *ggtt = node->ggtt;
>  	struct xe_device *xe = tile_to_xe(ggtt->tile);
> 
> --
> 2.34.1