USB: add remove_id sysfs attr for usb drivers
Accroding commit 0994375e, which is adding remove_id sysfs attr
for pci drivers, for management tools dynamically bind/unbind
a pci/usb devices to a specified drivers; with this patch,
the management tools can be simplied.
And the original code didn't handle the failure of
usb_create_newid_file, fixed in this patch.
Signed-off-by: CHENG Renquan <rqcheng@smu.edu.sg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 7a05bab..60a45f1 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -83,6 +83,47 @@
}
static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
+/**
+ * store_remove_id - remove a USB device ID from this driver
+ * @driver: target device driver
+ * @buf: buffer for scanning device ID data
+ * @count: input size
+ *
+ * Removes a dynamic usb device ID from this driver.
+ */
+static ssize_t
+store_remove_id(struct device_driver *driver, const char *buf, size_t count)
+{
+ struct usb_dynid *dynid, *n;
+ struct usb_driver *usb_driver = to_usb_driver(driver);
+ u32 idVendor = 0;
+ u32 idProduct = 0;
+ int fields = 0;
+ int retval = 0;
+
+ fields = sscanf(buf, "%x %x", &idVendor, &idProduct);
+ if (fields < 2)
+ return -EINVAL;
+
+ spin_lock(&usb_driver->dynids.lock);
+ list_for_each_entry_safe(dynid, n, &usb_driver->dynids.list, node) {
+ struct usb_device_id *id = &dynid->id;
+ if ((id->idVendor == idVendor) &&
+ (id->idProduct == idProduct)) {
+ list_del(&dynid->node);
+ kfree(dynid);
+ retval = 0;
+ break;
+ }
+ }
+ spin_unlock(&usb_driver->dynids.lock);
+
+ if (retval)
+ return retval;
+ return count;
+}
+static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id);
+
static int usb_create_newid_file(struct usb_driver *usb_drv)
{
int error = 0;
@@ -107,6 +148,21 @@
&driver_attr_new_id);
}
+static int
+usb_create_removeid_file(struct usb_driver *drv)
+{
+ int error = 0;
+ if (drv->probe != NULL)
+ error = driver_create_file(&drv->drvwrap.driver,
+ &driver_attr_remove_id);
+ return error;
+}
+
+static void usb_remove_removeid_file(struct usb_driver *drv)
+{
+ driver_remove_file(&drv->drvwrap.driver, &driver_attr_remove_id);
+}
+
static void usb_free_dynids(struct usb_driver *usb_drv)
{
struct usb_dynid *dynid, *n;
@@ -128,6 +184,16 @@
{
}
+static int
+usb_create_removeid_file(struct usb_driver *drv)
+{
+ return 0;
+}
+
+static void usb_remove_removeid_file(struct usb_driver *drv)
+{
+}
+
static inline void usb_free_dynids(struct usb_driver *usb_drv)
{
}
@@ -774,19 +840,34 @@
INIT_LIST_HEAD(&new_driver->dynids.list);
retval = driver_register(&new_driver->drvwrap.driver);
+ if (retval)
+ goto out;
- if (!retval) {
- pr_info("%s: registered new interface driver %s\n",
+ usbfs_update_special();
+
+ retval = usb_create_newid_file(new_driver);
+ if (retval)
+ goto out_newid;
+
+ retval = usb_create_removeid_file(new_driver);
+ if (retval)
+ goto out_removeid;
+
+ pr_info("%s: registered new interface driver %s\n",
usbcore_name, new_driver->name);
- usbfs_update_special();
- usb_create_newid_file(new_driver);
- } else {
- printk(KERN_ERR "%s: error %d registering interface "
+
+out:
+ return retval;
+
+out_removeid:
+ usb_remove_newid_file(new_driver);
+out_newid:
+ driver_unregister(&new_driver->drvwrap.driver);
+
+ printk(KERN_ERR "%s: error %d registering interface "
" driver %s\n",
usbcore_name, retval, new_driver->name);
- }
-
- return retval;
+ goto out;
}
EXPORT_SYMBOL_GPL(usb_register_driver);
@@ -806,6 +887,7 @@
pr_info("%s: deregistering interface driver %s\n",
usbcore_name, driver->name);
+ usb_remove_removeid_file(driver);
usb_remove_newid_file(driver);
usb_free_dynids(driver);
driver_unregister(&driver->drvwrap.driver);