On Mon, Jul 1, 2019 at 6:15 PM Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > > 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 Thanks, I'll fix these up when applying the patch.
