[09/54] Staging: panel: Prevent double-calling of parport_release - fix oops.

From: Greg KH
Date: Wed Aug 11 2010 - 20:25:50 EST


2.6.34-stable review patch. If anyone has any objections, please let us know.

------------------

From: Peter Huewe <peterhuewe@xxxxxx>

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@xxxxxx>
Acked-by: Willy Tarreau <w@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/staging/panel/panel.c | 2 ++
1 file changed, 2 insertions(+)

--- 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(
/* TODO: free all input signals */
parport_release(pprt);
parport_unregister_device(pprt);
+ pprt = NULL;
}
parport_unregister_driver(&panel_driver);
}


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