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-rw-r--r--drivers/usb/gadget/u_f.c3
-rw-r--r--drivers/usb/gadget/u_f.h16
2 files changed, 18 insertions, 1 deletions
diff --git a/drivers/usb/gadget/u_f.c b/drivers/usb/gadget/u_f.c
index 6811761..907f814 100644
--- a/drivers/usb/gadget/u_f.c
+++ b/drivers/usb/gadget/u_f.c
@@ -12,6 +12,7 @@
*/
#include "u_f.h"
+#include <linux/usb/ch9.h>
struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len)
{
@@ -20,6 +21,8 @@ struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len)
req = usb_ep_alloc_request(ep, GFP_ATOMIC);
if (req) {
req->length = len ?: default_len;
+ if (usb_endpoint_dir_out(ep->desc))
+ req->length = usb_ep_align(ep, req->length);
req->buf = kmalloc(req->length, GFP_ATOMIC);
if (!req->buf) {
usb_ep_free_request(ep, req);
diff --git a/drivers/usb/gadget/u_f.h b/drivers/usb/gadget/u_f.h
index 21b7571..69a1d10 100644
--- a/drivers/usb/gadget/u_f.h
+++ b/drivers/usb/gadget/u_f.h
@@ -47,8 +47,22 @@
struct usb_ep;
struct usb_request;
-/* Requests allocated via alloc_ep_req() must be freed by free_ep_req(). */
+/**
+ * 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
+ * @default_len: used if @len is not provided, ie, is 0
+ *
+ * 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, int default_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);
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