staging: vme_pio2: fix oops on module unloading

This patch forbids loading vme_pio2 module without specifing "num_bus" parameter.
Otherwise on module unloading pio2_exit() calls vme_unregister_driver() for not
registered pio2_driver.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Manohar Vanga <manohar.vanga@gmail.com>
Acked-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vme/devices/vme_pio2_core.c b/drivers/staging/vme/devices/vme_pio2_core.c
index 0331178..bf73ba2 100644 (file)
--- a/drivers/staging/vme/devices/vme_pio2_core.c
+++ b/drivers/staging/vme/devices/vme_pio2_core.c
@@ -162,11 +162,9 @@ static struct vme_driver pio2_driver = {
 
 static int __init pio2_init(void)
 {
-       int retval = 0;
-
        if (bus_num == 0) {
                pr_err("No cards, skipping registration\n");
-               goto err_nocard;
+               return -ENODEV;
        }
 
        if (bus_num > PIO2_CARDS_MAX) {
@@ -176,15 +174,7 @@ static int __init pio2_init(void)
        }
 
        /* Register the PIO2 driver */
-       retval = vme_register_driver(&pio2_driver, bus_num);
-       if (retval != 0)
-               goto err_reg;
-
-       return retval;
-
-err_reg:
-err_nocard:
-       return retval;
+       return  vme_register_driver(&pio2_driver, bus_num);
 }
 
 static int pio2_match(struct vme_dev *vdev)