Merge tag 'usb-for-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next

Felipe writes:

usb: patches for v4.9 merge window

This time around we have 92 non-merge commits. Most
of the changes are in drivers/usb/gadget (40.3%)
with drivers/usb/gadget/function being the most
active directory (27.2%).

As for UDC drivers, only dwc3 (26.5%) and dwc2
(12.7%) have really been active.

The most important changes for dwc3 are better
support for scatterlist and, again, throughput
improvements. While on dwc2 got some minor stability
fixes related to soft reset and FIFO usage.

Felipe Tonello has done some good work fixing up our
f_midi gadget and Tal Shorer has implemented a nice
API change for our ULPI bus.

Apart from these, we have our usual set of
non-critical fixes, spelling fixes, build warning
fixes, etc.

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
index 4247cc0..7d53a47 100644
--- a/drivers/usb/gadget/u_f.h
+++ b/drivers/usb/gadget/u_f.h
@@ -47,8 +47,21 @@
 struct usb_ep;
 struct usb_request;
 
-/* Requests allocated via alloc_ep_req() must be freed by free_ep_req(). */
-struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len);
+/**
+ * alloc_ep_req - returns a usb_request allocated by the gadget driver and
+ * allocates the request's buffer.
+ *
+ * @ep: the endpoint to allocate a usb_request
+ * @len: usb_requests's buffer suggested size
+ *
+ * In case @ep direction is OUT, the @len will be aligned to ep's
+ * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
+ * usb_requests's length (req->length) to refer to the allocated buffer size.
+ * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
+ */
+struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
+
+/* Frees a usb_request previously allocated by alloc_ep_req() */
 static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
 {
 	kfree(req->buf);