From bac2a909a096c9110525c18cbb8ce73c660d5f71 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 21 Jan 2015 02:17:42 +0100 Subject: 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-driver.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers/pci/pci-driver.c') 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)); } -- cgit v1.2.3