Staging: line6: only allocate a buffer if it is needed

Only allocate the version request buffer if it is needed, not when the
module starts up.  This will let us make the module_init path much
smaller.

CC: Markus Grabner <grabner@icg.tugraz.at>
CC: Stefan Hajnoczi <stefanha@gmail.com>
CC: Julia Lawall <julia@diku.dk>
CC: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 17 insertions, 30 deletions

diff --git a/drivers/staging/line6/driver.c b/drivers/staging/line6/driver.c
index 312905afe5e6..351e8606db3d 100644
--- a/drivers/staging/line6/driver.c
+++ b/drivers/staging/line6/driver.c
@@ -92,15 +92,10 @@ const unsigned char line6_midi_id[] = {
         Code to request version of POD, Variax interface
         (and maybe other devices).
 */
-static const char line6_request_version0[] = {
+static const char line6_request_version[] = {
         0xf0, 0x7e, 0x7f, 0x06, 0x01, 0xf7
 };
 
-/*
-        Copy of version request code with GFP_KERNEL flag for use in URB.
-*/
-static const char *line6_request_version;
-
 struct usb_line6 *line6_devices[LINE6_MAX_DEVICES];
 
 /**
@@ -336,8 +331,21 @@ int line6_send_raw_message_async(struct usb_line6 *line6, const char *buffer,
 */
 int line6_version_request_async(struct usb_line6 *line6)
 {
-        return line6_send_raw_message_async(line6, line6_request_version,
-                                            sizeof(line6_request_version0));
+        char *buffer;
+        int retval;
+
+        buffer = kmalloc(sizeof(line6_request_version), GFP_ATOMIC);
+        if (buffer == NULL) {
+                dev_err(line6->ifcdev, "Out of memory");
+                return -ENOMEM;
+        }
+
+        memcpy(buffer, line6_request_version, sizeof(line6_request_version));
+
+        retval = line6_send_raw_message_async(line6, buffer,
+                                              sizeof(line6_request_version));
+        kfree(buffer);
+        return retval;
 }
 
 /*
@@ -1297,29 +1305,9 @@ static struct usb_driver line6_driver = {
 */
 static int __init line6_init(void)
 {
-        int retval;
-
         printk(KERN_INFO "%s driver version %s\n", DRIVER_NAME, DRIVER_VERSION);
 
-        retval = usb_register(&line6_driver);
-
-        if (retval) {
-                err("usb_register failed. Error number %d", retval);
-                return retval;
-        }
-
-        line6_request_version = kmalloc(sizeof(line6_request_version0),
-                                        GFP_KERNEL);
-
-        if (line6_request_version == NULL) {
-                err("Out of memory");
-                return -ENOMEM;
-        }
-
-        memcpy((char *)line6_request_version, line6_request_version0,
-               sizeof(line6_request_version0));
-
-        return retval;
+        return usb_register(&line6_driver);
 }
 
 /*
@@ -1347,7 +1335,6 @@ static void __exit line6_exit(void)
         }
 
         usb_deregister(&line6_driver);
-        kfree(line6_request_version);
 }
 
 module_init(line6_init);