USB: gadget: f_printer: make usb_gadget_class a static const structure

Now that the driver core allows for struct class to be in read-only
memory, move the usb_gadget_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at load time.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230620094412.508580-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index b914256..076dd4c 100644 (file)
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -54,7 +54,10 @@
 #define DEFAULT_Q_LEN          10 /* same as legacy g_printer gadget */
 
 static int major, minors;
-static struct class *usb_gadget_class;
+static const struct class usb_gadget_class = {
+       .name = "usb_printer_gadget",
+};
+
 static DEFINE_IDA(printer_ida);
 static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
 
@@ -1120,7 +1123,7 @@ autoconf_fail:
 
        /* Setup the sysfs files for the printer gadget. */
        devt = MKDEV(major, dev->minor);
-       pdev = device_create(usb_gadget_class, NULL, devt,
+       pdev = device_create(&usb_gadget_class, NULL, devt,
                                  NULL, "g_printer%d", dev->minor);
        if (IS_ERR(pdev)) {
                ERROR(dev, "Failed to create device: g_printer\n");
@@ -1143,7 +1146,7 @@ autoconf_fail:
        return 0;
 
 fail_cdev_add:
-       device_destroy(usb_gadget_class, devt);
+       device_destroy(&usb_gadget_class, devt);
 
 fail_rx_reqs:
        while (!list_empty(&dev->rx_reqs)) {
@@ -1410,7 +1413,7 @@ static void printer_func_unbind(struct usb_configuration *c,
 
        dev = func_to_printer(f);
 
-       device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
+       device_destroy(&usb_gadget_class, MKDEV(major, dev->minor));
 
        /* Remove Character Device */
        cdev_del(&dev->printer_cdev);
@@ -1512,19 +1515,14 @@ static int gprinter_setup(int count)
        int status;
        dev_t devt;
 
-       usb_gadget_class = class_create("usb_printer_gadget");
-       if (IS_ERR(usb_gadget_class)) {
-               status = PTR_ERR(usb_gadget_class);
-               usb_gadget_class = NULL;
-               pr_err("unable to create usb_gadget class %d\n", status);
+       status = class_register(&usb_gadget_class);
+       if (status)
                return status;
-       }
 
        status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
        if (status) {
                pr_err("alloc_chrdev_region %d\n", status);
-               class_destroy(usb_gadget_class);
-               usb_gadget_class = NULL;
+               class_unregister(&usb_gadget_class);
                return status;
        }
 
@@ -1540,6 +1538,5 @@ static void gprinter_cleanup(void)
                unregister_chrdev_region(MKDEV(major, 0), minors);
                major = minors = 0;
        }
-       class_destroy(usb_gadget_class);
-       usb_gadget_class = NULL;
+       class_unregister(&usb_gadget_class);
 }