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

["Yadav, Arvind" <arvind.yadav@intel.com>]

On 01-09-2026 02:30, Rodrigo Vivi wrote:
> 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 ?!


Thanks for the review.
I do not think `NOTIFY_BAD` is needed here. A permanently wedged device 
should not prevent system suspend.
pm_notifier_call_chain_robust() passes the notifier result to 
notifier_to_errno(). NOTIFY_BAD becomes -EPERM, which will aborts system 
suspend.

~Arvind

>
>> +
>>   		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
>>