On Tue, Jan 20, 2015 at 7:17 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Commit f25c0ae2b4c4 (ACPI / PM: Avoid resuming devices in ACPI PM > domain during system suspend) modified the ACPI PM domain's system > suspend callbacks to allow devices attached to it to be left in the > runtime-suspended state during system suspend so as to optimize > the suspend process. > > This was based on the general mechanism introduced by commit > aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended > devices unnecessarily). > > Extend that approach to PCI devices by modifying the PCI bus type's > ->prepare callback to return 1 for devices that are runtime-suspended > when it is being executed and that are in a suitable power state and > need not be resumed going forward. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> I don't profess to understand this, and it seems like something you could merge via your PM tree. So I trust you to do the right thing with it :) Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > --- > > This version actually builds and need not be an RFC any more I suppose. > > --- > drivers/pci/pci-acpi.c | 17 +++++++++++++++++ > drivers/pci/pci-driver.c | 11 ++++++----- > drivers/pci/pci.c | 26 ++++++++++++++++++++++++++ > drivers/pci/pci.h | 6 ++++++ > 4 files changed, 55 insertions(+), 5 deletions(-) > > Index: linux-pm/drivers/pci/pci.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci.c > +++ linux-pm/drivers/pci/pci.c > @@ -521,6 +521,11 @@ static inline int platform_pci_run_wake( > pci_platform_pm->run_wake(dev, enable) : -ENODEV; > } > > +static inline bool platform_pci_need_resume(struct pci_dev *dev) > +{ > + return pci_platform_pm ? pci_platform_pm->need_resume(dev) : false; > +} > + > /** > * pci_raw_set_power_state - Use PCI PM registers to set the power state of > * given PCI device > @@ -1999,6 +2004,27 @@ bool pci_dev_run_wake(struct pci_dev *de > } > EXPORT_SYMBOL_GPL(pci_dev_run_wake); > > +/** > + * pci_dev_keep_suspended - Check if the device can stay in the suspended state. > + * @pci_dev: Device to check. > + * > + * Return 'true' if the device is runtime-suspended, it doesn't have to be > + * reconfigured due to wakeup settings difference between system and runtime > + * suspend and the current power state of it is suitable for the upcoming > + * (system) transition. > + */ > +bool pci_dev_keep_suspended(struct pci_dev *pci_dev) > +{ > + struct device *dev = &pci_dev->dev; > + > + if (!pm_runtime_suspended(dev) > + || (device_can_wakeup(dev) && !device_may_wakeup(dev)) > + || platform_pci_need_resume(pci_dev)) > + return false; > + > + return pci_target_state(pci_dev) == pci_dev->current_state; > +} > + > void pci_config_pm_runtime_get(struct pci_dev *pdev) > { > struct device *dev = &pdev->dev; > Index: linux-pm/drivers/pci/pci.h > =================================================================== > --- linux-pm.orig/drivers/pci/pci.h > +++ linux-pm/drivers/pci/pci.h > @@ -50,6 +50,10 @@ int pci_probe_reset_function(struct pci_ > * for given device (the device's wake-up capability has to be > * enabled by @sleep_wake for this feature to work) > * > + * @need_resume: returns 'true' if the given device (which is currently > + * suspended) needs to be resumed to be configured for system > + * wakeup. > + * > * If given platform is generally capable of power managing PCI devices, all of > * these callbacks are mandatory. > */ > @@ -59,6 +63,7 @@ struct pci_platform_pm_ops { > pci_power_t (*choose_state)(struct pci_dev *dev); > int (*sleep_wake)(struct pci_dev *dev, bool enable); > int (*run_wake)(struct pci_dev *dev, bool enable); > + bool (*need_resume)(struct pci_dev *dev); > }; > > int pci_set_platform_pm(struct pci_platform_pm_ops *ops); > @@ -67,6 +72,7 @@ void pci_power_up(struct pci_dev *dev); > void pci_disable_enabled_device(struct pci_dev *dev); > int pci_finish_runtime_suspend(struct pci_dev *dev); > int __pci_pme_wakeup(struct pci_dev *dev, void *ign); > +bool pci_dev_keep_suspended(struct pci_dev *dev); > void pci_config_pm_runtime_get(struct pci_dev *dev); > void pci_config_pm_runtime_put(struct pci_dev *dev); > void pci_pm_init(struct pci_dev *dev); > Index: linux-pm/drivers/pci/pci-acpi.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-acpi.c > +++ linux-pm/drivers/pci/pci-acpi.c > @@ -501,12 +501,29 @@ static int acpi_pci_run_wake(struct pci_ > return 0; > } > > +static bool acpi_pci_need_resume(struct pci_dev *dev) > +{ > + struct acpi_device *adev = ACPI_COMPANION(&dev->dev); > + > + if (!adev || !acpi_device_power_manageable(adev)) > + return false; > + > + if (device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count) > + return true; > + > + if (acpi_target_system_state() == ACPI_STATE_S0) > + return false; > + > + return !!adev->power.flags.dsw_present; > +} > + > static struct pci_platform_pm_ops acpi_pci_platform_pm = { > .is_manageable = acpi_pci_power_manageable, > .set_state = acpi_pci_set_power_state, > .choose_state = acpi_pci_choose_state, > .sleep_wake = acpi_pci_sleep_wake, > .run_wake = acpi_pci_run_wake, > + .need_resume = acpi_pci_need_resume, > }; > > void acpi_pci_add_bus(struct pci_bus *bus) > Index: linux-pm/drivers/pci/pci-driver.c > =================================================================== > --- linux-pm.orig/drivers/pci/pci-driver.c > +++ linux-pm/drivers/pci/pci-driver.c > @@ -653,7 +653,6 @@ static bool pci_has_legacy_pm_support(st > static int pci_pm_prepare(struct device *dev) > { > struct device_driver *drv = dev->driver; > - int error = 0; > > /* > * Devices having power.ignore_children set may still be necessary for > @@ -662,10 +661,12 @@ static int pci_pm_prepare(struct device > if (dev->power.ignore_children) > pm_runtime_resume(dev); > > - if (drv && drv->pm && drv->pm->prepare) > - error = drv->pm->prepare(dev); > - > - return error; > + if (drv && drv->pm && drv->pm->prepare) { > + int error = drv->pm->prepare(dev); > + if (error) > + return error; > + } > + return pci_dev_keep_suspended(to_pci_dev(dev)); > } > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html