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

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

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;
+
 		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