extcon: Remove potential problem when calling extcon_register_notifier()

This patch removes the potential problem of extcon_register_notifier()
when edev parameter is NULL. When edev is NULL, this function returns
the first extcon device which includes the sepecific external connector
of second paramter. But, it don't guarantee the same operation in all cases.
To remove this confusion and potential problem, this patch fixes it.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index 7c1e3a7b14e0c1f540a0bbe7d6b924b124561729..d0e367959c916b05fbcce4e69794891563f7357f 100644 (file)
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -906,35 +906,16 @@ int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
        unsigned long flags;
        int ret, idx = -EINVAL;
 
-       if (!nb)
+       if (!edev || !nb)
                return -EINVAL;
 
-       if (edev) {
-               idx = find_cable_index_by_id(edev, id);
-               if (idx < 0)
-                       return idx;
-
-               spin_lock_irqsave(&edev->lock, flags);
-               ret = raw_notifier_chain_register(&edev->nh[idx], nb);
-               spin_unlock_irqrestore(&edev->lock, flags);
-       } else {
-               struct extcon_dev *extd;
-
-               mutex_lock(&extcon_dev_list_lock);
-               list_for_each_entry(extd, &extcon_dev_list, entry) {
-                       idx = find_cable_index_by_id(extd, id);
-                       if (idx >= 0)
-                               break;
-               }
-               mutex_unlock(&extcon_dev_list_lock);
+       idx = find_cable_index_by_id(edev, id);
+       if (idx < 0)
+               return idx;
 
-               if (idx >= 0) {
-                       edev = extd;
-                       return extcon_register_notifier(extd, id, nb);
-               } else {
-                       ret = -ENODEV;
-               }
-       }
+       spin_lock_irqsave(&edev->lock, flags);
+       ret = raw_notifier_chain_register(&edev->nh[idx], nb);
+       spin_unlock_irqrestore(&edev->lock, flags);
 
        return ret;
 }