Re: [PATCH 10/13] drm/xe/ttm: Reject VRAM allocations on wedged devices

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Aug 27, 2026 at 03:47:58PM +0530, Arvind Yadav wrote:
> VRAM is no longer usable after the device is wedged. Reject new VRAM
> allocations with -ENOSPC so TTM can try another placement, such as TT.
> 
> An allocation racing with the wedge may still complete. The wedged fault
> path prevents new VRAM CPU mappings, and device teardown releases the
> resource.
> 
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Arvind Yadav <arvind.yadav@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_ttm_vram_mgr.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> index 05911904c1f9..d0b266672010 100644
> --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
> @@ -54,6 +54,7 @@ static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
>  			       const struct ttm_place *place,
>  			       struct ttm_resource **res)
>  {
> +	struct xe_device *xe = ttm_to_xe_device(tbo->bdev);
>  	struct xe_ttm_vram_mgr *mgr = to_xe_ttm_vram_mgr(man);
>  	struct xe_ttm_vram_mgr_resource *vres;
>  	struct gpu_buddy *mm = &mgr->mm;
> @@ -61,6 +62,9 @@ static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
>  	unsigned long lpfn;
>  	int err;
>  
> +	if (xe_device_wedged(xe))
> +		return -ENOSPC;

is -ENOSPC the right return here? -EIO? -ENOENT? -ENODEV? -ENXIO? -EPIPE?

> +
>  	lpfn = place->lpfn;
>  	if (!lpfn || lpfn > man->size >> PAGE_SHIFT)
>  		lpfn = man->size >> PAGE_SHIFT;
> -- 
> 2.43.0
>