[Intel-gfx] [PATCH] drm/i915: Do not cleanup obj with NULL bo->resource

[Matthew Auld]

On 20/09/2022 18:06, Nirmoy Das wrote:
> For delayed BO release i915_ttm_delete_mem_notify()
> gets called twice, once with proper bo->resource and
> another time with NULL. We shouldn't do anything for
> the 2nd time as we already cleanedup the obj once.
> 
> References: https://gitlab.freedesktop.org/drm/intel/-/issues/6850
> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>

Reviewed-by: Matthew Auld <matthew.auld at intel.com>

Christian, as per above it looks like ttm calls into the 
delete_mem_notify() hook twice if the object ends up on the delayed 
destroy list, is that expected/normal?

> ---
>   drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> index 0544b0a4a43a..e3fc38dd5db0 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> @@ -511,7 +511,7 @@ static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo)
>   	struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
>   	intel_wakeref_t wakeref = 0;
>   
> -	if (likely(obj)) {
> +	if (bo->resource && likely(obj)) {
>   		/* ttm_bo_release() already has dma_resv_lock */
>   		if (i915_ttm_cpu_maps_iomem(bo->resource))
>   			wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);