On Mon, Jul 01, 2019 at 12:44:25PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > 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: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account) > Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account) > Link: https://lore.kernel.org/linux-acpi/917d4399-2e22-67b1-9d54-808561f9083f@xxxxxxxx/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c > Reported-by: Robert R. Howell <RHowell@xxxxxxxx> > Tested-by: Robert R. Howell <RHowell@xxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > > -> v2: No changes. > > --- > drivers/acpi/device_pm.c | 13 +++++++------ > drivers/pci/pci-driver.c | 16 ++++++++-------- > 2 files changed, 15 insertions(+), 14 deletions(-) > > Index: linux-pm/drivers/acpi/device_pm.c > =================================================================== > --- linux-pm.orig/drivers/acpi/device_pm.c > +++ linux-pm/drivers/acpi/device_pm.c > @@ -1155,13 +1155,14 @@ EXPORT_SYMBOL_GPL(acpi_subsys_resume_ear > 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 > + * alwyas consistent with that. alwyas -> always > */ > - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) > - pm_runtime_resume(dev); > + pm_runtime_resume(dev); > > return pm_generic_freeze(dev); > } > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -1012,15 +1012,15 @@ static int pci_pm_freeze(struct device * > } > > /* > - * 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 > + * alwyas consistent with that. ditto > */ > - if (!dev_pm_smart_suspend_and_suspended(dev)) { > - pm_runtime_resume(dev); > - pci_dev->state_saved = false; > - } > + pm_runtime_resume(dev); > + pci_dev->state_saved = false; > > if (pm->freeze) { > int error; > > >
