Re: [PATCH 12/13] drm/xe: Skip PM notifier preparation for wedged devices

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

On Thu, Aug 27, 2026 at 03:48:00PM +0530, Arvind Yadav wrote:
> The system PM notifier runs before the PCI suspend callback and may evict
> BOs or submit migration work. This work must not start after the device
> has been declared wedged.
> 
> Skip PM preparation for a wedged device. Track whether preparation ran
> so the post callback only performs matching cleanup and releases the
> runtime PM reference when needed.
> 
> 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_device_types.h |  2 ++
>  drivers/gpu/drm/xe/xe_pm.c           | 10 ++++++++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 508ba3872e72..c9dc417878e7 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -471,6 +471,8 @@ struct xe_device {
>  
>  	/** @pm_notifier: Our PM notifier to perform actions in response to various PM events. */
>  	struct notifier_block pm_notifier;
> +	/** @pm_notifier_active: PM notifier prepare work was performed */
> +	bool pm_notifier_active;
>  	/** @pm_block: Completion to block validating tasks on suspend / hibernate prepare */
>  	struct completion pm_block;
>  	/** @rebind_resume_list: List of wq items to kick on resume. */
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index 720e083cd279..dd7fd170bc94 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -457,9 +457,14 @@ static int xe_pm_notifier_callback(struct notifier_block *nb,
>  	{
>  		struct xe_validation_ctx ctx;
>  
> +		/* Do not start PM preparation after a wedge is declared. */
> +		if (xe_device_wedged(xe))
> +			break;

perhaps we need to return NOTIFY_BAD ?!

> +
>  		reinit_completion(&xe->pm_block);
>  		xe_pm_block_begin_signalling();
>  		xe_pm_runtime_get(xe);
> +		xe->pm_notifier_active = true;
>  		(void)xe_validation_ctx_init(&ctx, &xe->val, NULL,
>  					     (struct xe_val_flags) {.exclusive = true});
>  		err = xe_bo_evict_all_user(xe);
> @@ -480,6 +485,11 @@ static int xe_pm_notifier_callback(struct notifier_block *nb,
>  	}
>  	case PM_POST_HIBERNATION:
>  	case PM_POST_SUSPEND:
> +		if (!xe->pm_notifier_active)
> +			break;
> +
> +		xe->pm_notifier_active = false;
> +
>  		complete_all(&xe->pm_block);
>  		xe_pm_wake_rebind_workers(xe);
>  		xe_bo_notifier_unprepare_all_pinned(xe);
> -- 
> 2.43.0
>