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USB: updates to usb_reset_composite_device()

This patch (as1023) updates the code in usb_reset_composite_device():

	Some local variable declarations are moved to inner loops.

	The interface locks are not acquired.  This isn't necessary
	any more; its only reason was to prevent an interface from
	being suspended or resumed during the reset.  But now
	interface power management is controlled by the USB device
	lock, not by the interface lock.

	The check for whether the interface is registered is removed.
	There doesn't seem to be any reason for checking; a driver
	for a non-registered interface deserves to be informed of
	device resets just as much as any other.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alan Stern 17 年之前
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共有 1 个文件被更改,包括 9 次插入23 次删除
  1. 9 23
      drivers/usb/core/hub.c

+ 9 - 23
drivers/usb/core/hub.c

@@ -3125,16 +3125,12 @@ EXPORT_SYMBOL(usb_reset_device);
  * this from a driver probe() routine after downloading new firmware.
  * For calls that might not occur during probe(), drivers should lock
  * the device using usb_lock_device_for_reset().
- *
- * The interface locks are acquired during the pre_reset stage and released
- * during the post_reset stage.  However if iface is not NULL and is
- * currently being probed, we assume that the caller already owns its
- * lock.
  */
 int usb_reset_composite_device(struct usb_device *udev,
 		struct usb_interface *iface)
 {
 	int ret;
+	int i;
 	struct usb_host_config *config = udev->actconfig;
 
 	if (udev->state == USB_STATE_NOTATTACHED ||
@@ -3151,16 +3147,11 @@ int usb_reset_composite_device(struct usb_device *udev,
 		iface = NULL;
 
 	if (config) {
-		int i;
-		struct usb_interface *cintf;
-		struct usb_driver *drv;
-
 		for (i = 0; i < config->desc.bNumInterfaces; ++i) {
-			cintf = config->interface[i];
-			if (cintf != iface)
-				down(&cintf->dev.sem);
-			if (device_is_registered(&cintf->dev) &&
-					cintf->dev.driver) {
+			struct usb_interface *cintf = config->interface[i];
+			struct usb_driver *drv;
+
+			if (cintf->dev.driver) {
 				drv = to_usb_driver(cintf->dev.driver);
 				if (drv->pre_reset)
 					(drv->pre_reset)(cintf);
@@ -3172,21 +3163,16 @@ int usb_reset_composite_device(struct usb_device *udev,
 	ret = usb_reset_device(udev);
 
 	if (config) {
-		int i;
-		struct usb_interface *cintf;
-		struct usb_driver *drv;
-
 		for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
-			cintf = config->interface[i];
-			if (device_is_registered(&cintf->dev) &&
-					cintf->dev.driver) {
+			struct usb_interface *cintf = config->interface[i];
+			struct usb_driver *drv;
+
+			if (cintf->dev.driver) {
 				drv = to_usb_driver(cintf->dev.driver);
 				if (drv->post_reset)
 					(drv->post_reset)(cintf);
 	/* FIXME: Unbind if post_reset returns an error or isn't defined */
 			}
-			if (cintf != iface)
-				up(&cintf->dev.sem);
 		}
 	}