UPSTREAM: extcon: Check for incorrect connection type in notifier register

If we call extcon_register_notifier() with the wrong cable type,
it blows up with an oops instead of returning an error code.
Let's be nice and fail gracefully given that the consumer might
not know if the cable is supported by the extcon provider.

Change-Id: I6e357a6af600dac82e9b1c30499b2d0a3d58d716
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
(cherry picked from commit a05f44c89ee1151b0da3ddd43d9e57d8f15b2f20)

diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index 87c9542bf9b8b624d2863ebd2c2142a94cf81843..3c3bdc0c2aa9ae7be093060530a98779dfd0ccb6 100644 (file)
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -415,6 +415,8 @@ int extcon_register_notifier(struct extcon_dev *edev, unsigned int id,
 
        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);
@@ -458,6 +460,8 @@ int extcon_unregister_notifier(struct extcon_dev *edev, unsigned int id,
                return -EINVAL;
 
        idx = find_cable_index_by_id(edev, id);
+       if (idx < 0)
+               return idx;
 
        spin_lock_irqsave(&edev->lock, flags);
        ret = raw_notifier_chain_unregister(&edev->nh[idx], nb);