asus-laptop: Fix rmmod of asus_laptop

The asus laptop driver conditionnaly registers leds in asus_led_register()
depending on their availability, but unconditionnaly unregisters them all at
exit time or when the module fails to load. Unregistering not registered leds
result in the following Oops. So we should check before unregistering.

 [<c032d2f9>] do_page_fault+0x511/0x5e9
 [<c032bae2>] error_code+0x6a/0x70
 [<c026abf8>] device_unregister+0x26/0x32
 [<f8864218>] led_classdev_unregister+0x58/0x94 [led_class]
 [<f88a90f8>] asus_led_exit+0x17/0x41 [asus_laptop]
 [<f88a91c9>] asus_laptop_exit+0xd/0x3f [asus_laptop]
 [<c013cee1>] sys_delete_module+0x17b/0x1a2
 [<c0106eae>] sysenter_past_esp+0x6b/0xa1

EIP: [<c026a9a3>] device_del+0xb/0x23a SS:ESP 0068:f594ef0c

Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/misc/asus-laptop.c b/drivers/misc/asus-laptop.c
index d0fc4fd212e6814ae1ce4f6c852ac30f5e8ec137..40db9f70148f4b1035861a416224d4b1606bf816 100644 (file)
--- a/drivers/misc/asus-laptop.c
+++ b/drivers/misc/asus-laptop.c
@@ -1072,7 +1072,8 @@ static void asus_backlight_exit(void)
 }
 
 #define  ASUS_LED_UNREGISTER(object)                           \
-       led_classdev_unregister(&object##_led)
+       if (object##_led.dev)                                   \
+               led_classdev_unregister(&object##_led)
 
 static void asus_led_exit(void)
 {