usb: gadget: configfs: simplify os_desc_item_to_gadget_info() helper

since os_desc_group is already a member of struct gadget_info,
we can simply just use container_of() to retrieve the latter,
without needing to dereference the cg_item's parent pointer.

use os_desc_item_to_gadget_info() helper in os_desc (un)link function.

Reviewed-by: Jack Pham <quic_jackp@quicinc.com>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1637211213-16400-2-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 36c611d..ac35fea 100644 (file)
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -791,7 +791,8 @@ static inline struct os_desc *to_os_desc(struct config_item *item)
 static inline struct gadget_info *os_desc_item_to_gadget_info(
                struct config_item *item)
 {
-       return to_gadget_info(to_os_desc(item)->group.cg_item.ci_parent);
+       return container_of(to_config_group(item),
+                       struct gadget_info, os_desc_group);
 }
 
 static ssize_t os_desc_use_show(struct config_item *item, char *page)
@@ -895,8 +896,7 @@ static void os_desc_attr_release(struct config_item *item)
 static int os_desc_link(struct config_item *os_desc_ci,
                        struct config_item *usb_cfg_ci)
 {
-       struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
-                                       struct gadget_info, os_desc_group);
+       struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
        struct usb_composite_dev *cdev = &gi->cdev;
        struct config_usb_cfg *c_target =
                container_of(to_config_group(usb_cfg_ci),
@@ -930,8 +930,7 @@ out:
 static void os_desc_unlink(struct config_item *os_desc_ci,
                          struct config_item *usb_cfg_ci)
 {
-       struct gadget_info *gi = container_of(to_config_group(os_desc_ci),
-                                       struct gadget_info, os_desc_group);
+       struct gadget_info *gi = os_desc_item_to_gadget_info(os_desc_ci);
        struct usb_composite_dev *cdev = &gi->cdev;
 
        mutex_lock(&gi->lock);