[PATCH 6.6 029/105] usb: gadget: Introduce free_usb_request helper

Greg Kroah-Hartman
2025-10-21T19:53:42Z

From: Kuen-Han Tsai <khtsai@google.com>

[ Upstream commit 201c53c687f2b55a7cc6d9f4000af4797860174b ]

Introduce the free_usb_request() function that frees both the request's
buffer and the request itself.

This function serves as the cleanup callback for DEFINE_FREE() to enable
automatic, scope-based cleanup for usb_request pointers.

Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Link: https://lore.kernel.org/r/20250916-ready-v1-2-4997bf277548@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20250916-ready-v1-2-4997bf277548@google.com
Stable-dep-of: 75a5b8d4ddd4 ("usb: gadget: f_ncm: Refactor bind path to use __free()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/usb/gadget.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -15,6 +15,7 @@
#ifndef __LINUX_USB_GADGET_H
#define __LINUX_USB_GADGET_H

+#include <linux/cleanup.h>
#include <linux/configfs.h>
#include <linux/device.h>
#include <linux/errno.h>
@@ -291,6 +292,28 @@ static inline void usb_ep_fifo_flush(str

/*-------------------------------------------------------------------------*/

+/**
+ * free_usb_request - frees a usb_request object and its buffer
+ * @req: the request being freed
+ *
+ * This helper function frees both the request's buffer and the request object
+ * itself by calling usb_ep_free_request(). Its signature is designed to be used
+ * with DEFINE_FREE() to enable automatic, scope-based cleanup for usb_request
+ * pointers.
+ */
+static inline void free_usb_request(struct usb_request *req)
+{
+ if (!req)
+ return;
+
+ kfree(req->buf);
+ usb_ep_free_request(req->ep, req);
+}
+
+DEFINE_FREE(free_usb_request, struct usb_request *, free_usb_request(_T))
+
+/*-------------------------------------------------------------------------*/
+
struct usb_dcd_config_params {
__u8 bU1devExitLat; /* U1 Device exit Latency */
#define USB_DEFAULT_U1_DEV_EXIT_LAT 0x01 /* Less then 1 microsec */