Staging: panel: Prevent double-calling of parport_release - fix oops.

commit 060132ae42cce3f9d2fd34d9a17b98362b44b9f9 upstream.

This patch prevents the code from calling parport_release and
parport_unregister_device twice with the same arguments - and thus fixes an oops.

Rationale:
After the first call the parport is already released and the
handle isn't valid anymore and calling parport_release and
parport_unregister_device twice isn't a good idea.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index 377884f3480d8e28a1a4467c3e6270a274dcad94..d1ed0ebb712ded11db5250d7a471aa625bf6fded 100644 (file)
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -2180,6 +2180,7 @@ int panel_init(void)
                if (pprt) {
                        parport_release(pprt);
                        parport_unregister_device(pprt);
+                       pprt = NULL;
                }
                parport_unregister_driver(&panel_driver);
                printk(KERN_ERR "Panel driver version " PANEL_VERSION
@@ -2229,6 +2230,7 @@ static void __exit panel_cleanup_module(void)
                /* TODO: free all input signals */
                parport_release(pprt);
                parport_unregister_device(pprt);
+               pprt = NULL;
        }
        parport_unregister_driver(&panel_driver);
 }