From d491f2b75237ef37d8867830ab7fad8d9659e853 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 17 May 2019 11:08:50 +0200 Subject: PCI: PM: Avoid possible suspend-to-idle issue If a PCI driver leaves the device handled by it in D0 and calls pci_save_state() on the device in its ->suspend() or ->suspend_late() callback, it can expect the device to stay in D0 over the whole s2idle cycle. However, that may not be the case if there is a spurious wakeup while the system is suspended, because in that case pci_pm_suspend_noirq() will run again after pci_pm_resume_noirq() which calls pci_restore_state(), via pci_pm_default_resume_early(), so state_saved is cleared and the second iteration of pci_pm_suspend_noirq() will invoke pci_prepare_to_sleep() which may change the power state of the device. To avoid that, add a new internal flag, skip_bus_pm, that will be set by pci_pm_suspend_noirq() when it runs for the first time during the given system suspend-resume cycle if the state of the device has been saved already and the device is still in D0. Setting that flag will cause the next iterations of pci_pm_suspend_noirq() to set state_saved for pci_pm_resume_noirq(), so that it always restores the device state from the originally saved data, and avoid calling pci_prepare_to_sleep() for the device. Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle") Signed-off-by: Rafael J. Wysocki Reviewed-by: Keith Busch Reviewed-by: Mika Westerberg --- include/linux/pci.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/pci.h b/include/linux/pci.h index 4a5a84d7bdd4..dd436da7eccc 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -344,6 +344,7 @@ struct pci_dev { D3cold, not set for devices powered on/off by the corresponding bridge */ + unsigned int skip_bus_pm:1; /* Internal: Skip bus-level PM */ unsigned int ignore_hotplug:1; /* Ignore hotplug events */ unsigned int hotplug_user_indicators:1; /* SlotCtl indicators controlled exclusively by -- cgit