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 <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 6 insertions, 0 deletions

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);