Commit 501debd4 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM: ACPI/PCI: Resume all devices during hibernation 

Both the PCI bus type and the ACPI PM domain avoid resuming
runtime-suspended devices with DPM_FLAG_SMART_SUSPEND set during
hibernation (before creating the snapshot image of system memory),
but that turns out to be a mistake.  It leads to functional issues
and adds complexity that's hard to justify.

For this reason, resume all runtime-suspended PCI devices and all
devices in the ACPI PM domains before creating a snapshot image of
system memory during hibernation.

Fixes: 05087360 (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Fixes: c4b65157 (PCI / PM: Take SMART_SUSPEND driver flag into account)
Link: https://lore.kernel.org/linux-acpi/917d4399-2e22-67b1-9d54-808561f9083f@uwyo.edu/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c


Reported-by: default avatarRobert R. Howell <RHowell@uwyo.edu>
Tested-by: default avatarRobert R. Howell <RHowell@uwyo.edu>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 2f02a7ec

drivers/acpi/device_pm.c

+7 −6
Original line number Diff line number Diff line
@@ -1112,12 +1112,13 @@ EXPORT_SYMBOL_GPL(acpi_subsys_resume_early); 
int acpi_subsys_freeze(struct device *dev)

{

	/*

	 * This used to be done in acpi_subsys_prepare() for all devices and

	 * some drivers may depend on it, so do it here.  Ideally, however,

	 * runtime-suspended devices should not be touched during freeze/thaw

	 * transitions.

	 * Resume all runtime-suspended devices before creating a snapshot

	 * image of system memory, because the restore kernel generally cannot

	 * be expected to always handle them consistently and they need to be

	 * put into the runtime-active metastate during system resume anyway,

	 * so it is better to ensure that the state saved in the image will be

	 * always consistent with that.

	 */

	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))

	pm_runtime_resume(dev);



	return pm_generic_freeze(dev);

drivers/pci/pci-driver.c

+8 −8
Original line number Diff line number Diff line
@@ -972,15 +972,15 @@ static int pci_pm_freeze(struct device *dev) 
	}



	/*

	 * This used to be done in pci_pm_prepare() for all devices and some

	 * drivers may depend on it, so do it here.  Ideally, runtime-suspended

	 * devices should not be touched during freeze/thaw transitions,

	 * however.

	 * Resume all runtime-suspended devices before creating a snapshot

	 * image of system memory, because the restore kernel generally cannot

	 * be expected to always handle them consistently and they need to be

	 * put into the runtime-active metastate during system resume anyway,

	 * so it is better to ensure that the state saved in the image will be

	 * always consistent with that.

	 */

	if (!dev_pm_smart_suspend_and_suspended(dev)) {

	pm_runtime_resume(dev);

	pci_dev->state_saved = false;

	}



	if (pm->freeze) {

		int error;

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