Commit 5ebffd7c authored Jul 01, 2007 by Maxime Austruy Committed by Linus Torvalds Jul 01, 2007

asus_acpi: fix oops on non-asus machines

If asus_acpi_init doesn't find any device it knows about, it mistakenly
returns a "success" error code even though it cleans up after itself. Later
when trying to rmmod asus_acpi, the module_exit routine would try to clean up
one more time and we would end up calling
acpi_bus_unregister_driver(&asus_hotk_driver) twice. This patch addresses
this first problem by returning -ENODEV when no appropriate device is found.

Then there was also another bug with the code handling the return value of
backlight_device_register. If this function ever failed, the driver would
cleanup by calling the module_exit routine from module_init, but it would
still return "success". So any attempt to rmmod this module would result in
asus_acpi_exit being called twice but it's not ready to handle it (I haven't
hit this bug, just found it by code inspection). This patch fixes that by
inserting a return -ENODEV; at the end of this error handling path.

Signed-off-by: Maxime Austruy <maxime@tralhalla.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent d80d0217

drivers/acpi/asus_acpi.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1398,7 +1398,7 @@ static int __init asus_acpi_init(void)
		if (!asus_hotk_found) {
		acpi_bus_unregister_driver(&asus_hotk_driver);
		remove_proc_entry(PROC_ASUS, acpi_root_dir);
		return result;
		return -ENODEV;
		}

		asus_backlight_device = backlight_device_register("asus",NULL,NULL,
		@@ -1407,6 +1407,7 @@ static int __init asus_acpi_init(void)
		printk(KERN_ERR "Could not register asus backlight device\n");
		asus_backlight_device = NULL;
		asus_acpi_exit();
		return -ENODEV;
		}
		asus_backlight_device->props.max_brightness = 15;