*/
+#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/usb.h>
-#include <linux/mutex.h>
#include "usb.h"
-static BLOCKING_NOTIFIER_HEAD(usb_notifier_list);
+
+static struct notifier_block *usb_notifier_list;
+static DECLARE_MUTEX(usb_notifier_lock);
+
+static void usb_notifier_chain_register(struct notifier_block **list,
+ struct notifier_block *n)
+{
+ down(&usb_notifier_lock);
+ while (*list) {
+ if (n->priority > (*list)->priority)
+ break;
+ list = &((*list)->next);
+ }
+ n->next = *list;
+ *list = n;
+ up(&usb_notifier_lock);
+}
+
+static void usb_notifier_chain_unregister(struct notifier_block **nl,
+ struct notifier_block *n)
+{
+ down(&usb_notifier_lock);
+ while ((*nl)!=NULL) {
+ if ((*nl)==n) {
+ *nl = n->next;
+ goto exit;
+ }
+ nl=&((*nl)->next);
+ }
+exit:
+ up(&usb_notifier_lock);
+}
+
+static int usb_notifier_call_chain(struct notifier_block **n,
+ unsigned long val, void *v)
+{
+ int ret=NOTIFY_DONE;
+ struct notifier_block *nb = *n;
+
+ down(&usb_notifier_lock);
+ while (nb) {
+ ret = nb->notifier_call(nb,val,v);
+ if (ret&NOTIFY_STOP_MASK) {
+ goto exit;
+ }
+ nb = nb->next;
+ }
+exit:
+ up(&usb_notifier_lock);
+ return ret;
+}
/**
* usb_register_notify - register a notifier callback whenever a usb change happens
*/
void usb_register_notify(struct notifier_block *nb)
{
- blocking_notifier_chain_register(&usb_notifier_list, nb);
+ usb_notifier_chain_register(&usb_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(usb_register_notify);
*/
void usb_unregister_notify(struct notifier_block *nb)
{
- blocking_notifier_chain_unregister(&usb_notifier_list, nb);
+ usb_notifier_chain_unregister(&usb_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(usb_unregister_notify);
void usb_notify_add_device(struct usb_device *udev)
{
- blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
+ usb_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
}
void usb_notify_remove_device(struct usb_device *udev)
{
- /* Protect against simultaneous usbfs open */
- mutex_lock(&usbfs_mutex);
- blocking_notifier_call_chain(&usb_notifier_list,
- USB_DEVICE_REMOVE, udev);
- mutex_unlock(&usbfs_mutex);
+ usb_notifier_call_chain(&usb_notifier_list, USB_DEVICE_REMOVE, udev);
}
void usb_notify_add_bus(struct usb_bus *ubus)
{
- blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
+ usb_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
}
void usb_notify_remove_bus(struct usb_bus *ubus)
{
- blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
+ usb_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
}