diff options
Diffstat (limited to 'drivers/usb/core/usb.c')
| -rw-r--r-- | drivers/usb/core/usb.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 6ecfdce4f84..e89dbd43e95 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -1414,14 +1414,33 @@ void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe, usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } +static int verify_suspended(struct device *dev, void *unused) +{ + return (dev->power.power_state.event == PM_EVENT_ON) ? -EBUSY : 0; +} + static int usb_generic_suspend(struct device *dev, pm_message_t message) { struct usb_interface *intf; struct usb_driver *driver; int status; - if (dev->driver == &usb_generic_driver) - return usb_suspend_device (to_usb_device(dev), message); + /* USB devices enter SUSPEND state through their hubs, but can be + * marked for FREEZE as soon as their children are already idled. + */ + if (dev->driver == &usb_generic_driver) { + if (dev->power.power_state.event == message.event) + return 0; + /* we need to rule out bogus requests through sysfs */ + status = device_for_each_child(dev, NULL, verify_suspended); + if (status) + return status; + if (message.event == PM_EVENT_FREEZE) { + dev->power.power_state = message; + return 0; + } + return usb_suspend_device (to_usb_device(dev)); + } if ((dev->driver == NULL) || (dev->driver_data == &usb_generic_driver_data)) |