From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> 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/917d4399-2e22-67b1-9d54-808561f90...@uwyo.edu/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c Reported-by: Robert R. Howell <rhow...@uwyo.edu> Tested-by: Robert R. Howell <rhow...@uwyo.edu> Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> --- 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. */ - 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. */ - 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;
