[PATCH] USB: Convert usbtest to the new altsetting regime

This patch converts the usbtest driver to the new way altsettings work.
The largest change is to remove the assumptions that altsetting numbers
lie in the correct range (a debugging message is logged if they don't but
execution doesn't stop) and that the array is sorted by number.

drivers/usb/misc/usbtest.c

@@ -490,7 +490,7 @@ static int set_altsetting (struct usbtest_dev *dev, int alternate)
 	struct usb_interface		*iface = dev->intf;
 	struct usb_device		*udev;
 
-	if (alternate < 0 || alternate >= iface->num_altsetting)
+	if (alternate < 0 || alternate >= 256)
 		return -EINVAL;
 
 	udev = interface_to_usbdev (iface);
@@ -556,23 +556,19 @@ static int ch9_postconfig (struct usbtest_dev *dev)
 {
 	struct usb_interface	*iface = dev->intf;
 	struct usb_device	*udev = interface_to_usbdev (iface);
-	int			i, retval;
+	int			i, alt, retval;
 
 	/* [9.2.3] if there's more than one altsetting, we need to be able to
 	 * set and get each one.  mostly trusts the descriptors from usbcore.
 	 */
 	for (i = 0; i < iface->num_altsetting; i++) {
 
-		/* 9.2.3 constrains the range here, and Linux ensures
-		 * they're ordered meaningfully in this array
-		 */
-		if (iface->altsetting [i].desc.bAlternateSetting != i) {
+		/* 9.2.3 constrains the range here */
+		alt = iface->altsetting [i].desc.bAlternateSetting;
+		if (alt < 0 || alt >= iface->num_altsetting) {
 			dev_dbg (&iface->dev,
 					"invalid alt [%d].bAltSetting = %d\n",
-					i, 
-					iface->altsetting [i].desc
-						.bAlternateSetting);
-			return -EDOM;
+					i, alt);
 		}
 
 		/* [real world] get/set unimplemented if there's only one */
@@ -580,18 +576,18 @@ static int ch9_postconfig (struct usbtest_dev *dev)
 			continue;
 
 		/* [9.4.10] set_interface */
-		retval = set_altsetting (dev, i);
+		retval = set_altsetting (dev, alt);
 		if (retval) {
 			dev_dbg (&iface->dev, "can't set_interface = %d, %d\n",
-					i, retval);
+					alt, retval);
 			return retval;
 		}
 
 		/* [9.4.4] get_interface always works */
 		retval = get_altsetting (dev);
-		if (retval != i) {
+		if (retval != alt) {
 			dev_dbg (&iface->dev, "get alt should be %d, was %d\n",
-					i, retval);
+					alt, retval);
 			return (retval < 0) ? retval : -EDOM;
 		}