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Diffstat (limited to 'drivers/usb/gadget/u_f.h')
-rw-r--r--drivers/usb/gadget/u_f.h17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
index 4247cc098a89..7d53a4773d1a 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);