PM: Allow USB devices to suspend/resume asynchronously

Set power.async_suspend for USB devices, endpoints and interfaces,
allowing them to be suspended and resumed asynchronously during
system sleep transitions.

The power.async_suspend flag is also set for devices that don't have
suspend or resume callbacks, because otherwise they would make the
main suspend/resume thread wait for their "asynchronous" children
(during suspend) or parents (during resume), effectively negating the
possible gains from executing these devices' suspend and resume
callbacks asynchronously.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
index fdfaa78..d26b9ea 100644 (file)
--- a/drivers/usb/core/endpoint.c
+++ b/drivers/usb/core/endpoint.c
@@ -186,6 +186,7 @@ int usb_create_ep_devs(struct device *parent,
        ep_dev->dev.parent = parent;
        ep_dev->dev.release = ep_device_release;
        dev_set_name(&ep_dev->dev, "ep_%02x", endpoint->desc.bEndpointAddress);
+       device_enable_async_suspend(&ep_dev->dev);
 
        retval = device_register(&ep_dev->dev);
        if (retval)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 35cc8b9..20ecb4c 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1817,6 +1817,7 @@ int usb_new_device(struct usb_device *udev)
        /* Tell the world! */
        announce_device(udev);
 
+       device_enable_async_suspend(&udev->dev);
        /* Register the device.  The device driver is responsible
         * for configuring the device and invoking the add-device
         * notifier chain (used by usbfs and possibly others).

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..df73574 100644 (file)
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1867,6 +1867,7 @@ free_interfaces:
                        "adding %s (config #%d, interface %d)\n",
                        dev_name(&intf->dev), configuration,
                        intf->cur_altsetting->desc.bInterfaceNumber);
+               device_enable_async_suspend(&intf->dev);
                ret = device_add(&intf->dev);
                if (ret != 0) {
                        dev_err(&dev->dev, "device_add(%s) --> %d\n",