staging: gpib: agilent_82357a: Handle gpib_register_driver() errors

The usb_register() function can fail and returns an error value which
is not returned. The function gpib_register_driver() can also fail
which can result in semi-registered module.

In case gpib_register_driver() fails unregister the previous usb driver
registering function. Return the error value if gpib_register_driver()
or usb_register() functions fail. Add pr_err when registering driver
fails also indicating the error value.

Signed-off-by: Nihar Chaithanya <niharchaithanya@gmail.com>
Link: https://lore.kernel.org/r/20241230185633.175690-4-niharchaithanya@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
index bf05fb4a736b3f4b7f9b12e3cac4d1b53a6cd49c..261fb6d2e9916de89da3f51fff9f23a9088f618a 100644 (file)
--- a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
+++ b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c
@@ -1691,12 +1691,24 @@ static struct usb_driver agilent_82357a_bus_driver = {
 static int __init agilent_82357a_init_module(void)
 {
        int i;
+       int ret;
 
        pr_info("agilent_82357a_gpib driver loading");
        for (i = 0; i < MAX_NUM_82357A_INTERFACES; ++i)
                agilent_82357a_driver_interfaces[i] = NULL;
-       usb_register(&agilent_82357a_bus_driver);
-       gpib_register_driver(&agilent_82357a_gpib_interface, THIS_MODULE);
+
+       ret = usb_register(&agilent_82357a_bus_driver);
+       if (ret) {
+               pr_err("agilent_82357a: usb_register failed: error = %d\n", ret);
+               return ret;
+       }
+
+       ret = gpib_register_driver(&agilent_82357a_gpib_interface, THIS_MODULE);
+       if (ret) {
+               pr_err("agilent_82357a: gpib_register_driver failed: error = %d\n", ret);
+               usb_deregister(&agilent_82357a_bus_driver);
+               return ret;
+       }
 
        return 0;
 }