- Move scratch data from the USB bus structure to the USB device structure

so that simultaneous access cannot happen. Protect scratch area using
the enumeration lock. Also reduce stack usage in usbd_transfer_setup()
by moving some big stack members to the scratch area. This saves around
200 bytes of stack.
- Fix a whitespace.

MFC after:	1 week

1 files changed, 15 insertions, 7 deletions

diff --git a/sys/dev/usb/usb_util.c b/sys/dev/usb/usb_util.c
index f9fec76..ffd005b 100644
--- a/sys/dev/usb/usb_util.c
+++ b/sys/dev/usb/usb_util.c
@@ -75,6 +75,7 @@ device_set_usb_desc(device_t dev)
 	struct usb_interface *iface;
 	char *temp_p;
 	usb_error_t err;
+	uint8_t do_unlock;
 
 	if (dev == NULL) {
 		/* should not happen */
@@ -96,19 +97,26 @@ device_set_usb_desc(device_t dev)
 		err = 0;
 	}
 
-	temp_p = (char *)udev->bus->scratch[0].data;
+	/* Protect scratch area */
+	do_unlock = usbd_enum_lock(udev);
 
-	if (!err) {
+	temp_p = (char *)udev->scratch.data;
+
+	if (err == 0) {
 		/* try to get the interface string ! */
-		err = usbd_req_get_string_any
-		    (udev, NULL, temp_p,
-		    sizeof(udev->bus->scratch), iface->idesc->iInterface);
+		err = usbd_req_get_string_any(udev, NULL, temp_p,
+		    sizeof(udev->scratch.data),
+		    iface->idesc->iInterface);
 	}
-	if (err) {
+	if (err != 0) {
 		/* use default description */
 		usb_devinfo(udev, temp_p,
-		    sizeof(udev->bus->scratch));
+		    sizeof(udev->scratch.data));
 	}
+
+	if (do_unlock)
+		usbd_enum_unlock(udev);
+
 	device_set_desc_copy(dev, temp_p);
 	device_printf(dev, "<%s> on %s\n", temp_p,
 	    device_get_nameunit(udev->bus->bdev));