From bac2a909a096c9110525c18cbb8ce73c660d5f71 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 21 Jan 2015 02:17:42 +0100 Subject: [PATCH] PCI / PM: Avoid resuming PCI devices during system suspend 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 Acked-by: Bjorn Helgaas --- 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(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 3542150fc8a3..489063987325 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -501,12 +501,29 @@ static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 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) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 887e6bd95af7..741023e94008 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -653,7 +653,6 @@ static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev) 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 *dev) 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)); } diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index cab05f31223f..7a671abceccc 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -521,6 +521,11 @@ static inline int platform_pci_run_wake(struct pci_dev *dev, bool enable) 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 *dev) } 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; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 8aff29a804ff..febb3db9f742 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -50,6 +50,10 @@ int pci_probe_reset_function(struct pci_dev *dev); * 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); -- 2.20.1