* @vbus: for udcs who care about vbus status, this value is real vbus status;
* for udcs who do not care about vbus status, this value is always true
* @started: the UDC's started state. True if the UDC had started.
+ * @allow_connect: Indicates whether UDC is allowed to be pulled up.
+ * Set/cleared by gadget_(un)bind_driver() after gadget driver is bound or
+ * unbound.
*
* This represents the internal data structure which is used by the UDC-class
* to hold information about udc driver and gadget together.
struct list_head list;
bool vbus;
bool started;
+ bool allow_connect;
+ struct work_struct vbus_work;
};
static struct class *udc_class;
goto out;
}
- if (gadget->deactivated) {
+ if (gadget->deactivated || !gadget->udc->allow_connect) {
/*
* If gadget is deactivated we only save new state.
* Gadget will be connected automatically after activation.
usb_gadget_disconnect(udc->gadget);
}
+static void vbus_event_work(struct work_struct *work)
+{
+ struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work);
+
+ usb_udc_connect_control(udc);
+}
+
/**
* usb_udc_vbus_handler - updates the udc core vbus status, and try to
* connect or disconnect gadget
*
* The udc driver calls it when it wants to connect or disconnect gadget
* according to vbus status.
+ *
+ * This function can be invoked from interrupt context by irq handlers of
+ * the gadget drivers, however, usb_udc_connect_control() has to run in
+ * non-atomic context due to the following:
+ * a. Some of the gadget driver implementations expect the ->pullup
+ * callback to be invoked in non-atomic context.
+ * b. usb_gadget_disconnect() acquires udc_lock which is a mutex.
+ * Hence offload invocation of usb_udc_connect_control() to workqueue.
*/
void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status)
{
if (udc) {
udc->vbus = status;
- usb_udc_connect_control(udc);
+ schedule_work(&udc->vbus_work);
}
}
EXPORT_SYMBOL_GPL(usb_udc_vbus_handler);
mutex_lock(&udc_lock);
list_add_tail(&udc->list, &udc_list);
mutex_unlock(&udc_lock);
+ INIT_WORK(&udc->vbus_work, vbus_event_work);
ret = device_add(&udc->dev);
if (ret)
flush_work(&gadget->work);
device_del(&gadget->dev);
ida_free(&gadget_id_numbers, gadget->id_number);
+ cancel_work_sync(&udc->vbus_work);
device_unregister(&udc->dev);
}
EXPORT_SYMBOL_GPL(usb_del_gadget);
if (ret)
goto err_start;
usb_gadget_enable_async_callbacks(udc);
+ udc->allow_connect = true;
usb_udc_connect_control(udc);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
+ udc->allow_connect = false;
+ cancel_work_sync(&udc->vbus_work);
usb_gadget_disconnect(gadget);
usb_gadget_disable_async_callbacks(udc);
if (gadget->irq)