diff options
Diffstat (limited to 'drivers/usb/core/message.c')
| -rw-r--r-- | drivers/usb/core/message.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index cc47d36798b..aadf29f09c4 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1441,6 +1441,46 @@ static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev, return retval; } + +/* + * Internal function to queue a device reset + * + * This is initialized into the workstruct in 'struct + * usb_device->reset_ws' that is launched by + * message.c:usb_set_configuration() when initializing each 'struct + * usb_interface'. + * + * It is safe to get the USB device without reference counts because + * the life cycle of @iface is bound to the life cycle of @udev. Then, + * this function will be ran only if @iface is alive (and before + * freeing it any scheduled instances of it will have been cancelled). + * + * We need to set a flag (usb_dev->reset_running) because when we call + * the reset, the interfaces might be unbound. The current interface + * cannot try to remove the queued work as it would cause a deadlock + * (you cannot remove your work from within your executing + * workqueue). This flag lets it know, so that + * usb_cancel_queued_reset() doesn't try to do it. + * + * See usb_queue_reset_device() for more details + */ +void __usb_queue_reset_device(struct work_struct *ws) +{ + int rc; + struct usb_interface *iface = + container_of(ws, struct usb_interface, reset_ws); + struct usb_device *udev = interface_to_usbdev(iface); + + rc = usb_lock_device_for_reset(udev, iface); + if (rc >= 0) { + iface->reset_running = 1; + usb_reset_device(udev); + iface->reset_running = 0; + usb_unlock_device(udev); + } +} + + /* * usb_set_configuration - Makes a particular device setting be current * @dev: the device whose configuration is being updated @@ -1611,6 +1651,7 @@ free_interfaces: intf->dev.type = &usb_if_device_type; intf->dev.groups = usb_interface_groups; intf->dev.dma_mask = dev->dev.dma_mask; + INIT_WORK(&intf->reset_ws, __usb_queue_reset_device); device_initialize(&intf->dev); mark_quiesced(intf); dev_set_name(&intf->dev, "%d-%s:%d.%d", |