On Sun, 29 Dec 2024 17:46:59 +0100 Maciej S. Szmigiero wrote:

+	if (pci_registered)
+		pci_unregister_driver(&iosm_ipc_driver);
+
+	unregister_pm_notifier(&pm_notifier);

The ordering here should be inverted so that you're sure notifier can't
run in parallel.

But I think the notifier is an overkill, there's gotta be an op that
runs. pci_driver::shutdown ? dev_pm_ops::freeze / thaw ?

If you repost please make sure to CC the PCI list, folks there will
know how hibernation is supposed to be handled for sure. Note that
patch 1 is already in Linus's tree so repost just patch 2.