[PATCH v2] phy: Fix error handling in tegra_xusb_pad_init

[Ma Ke <make24@iscas.ac.cn>]

If device_add() fails, do not use device_unregister() for error
handling. device_unregister() consists two functions: device_del() and
put_device(). device_unregister() should only be called after
device_add() succeeded because device_del() undoes what device_add()
does if successful.

As comment of device_add() says, 'if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count'.

In tegra_xusb_pad_init(), both dev_set_name() and device_add() may
fail. In either case, we should only use put_device(). After
device_initialize(), the device has a reference count of 1. If
dev_set_name() fails, device_add() has not been called. If
device_add() fails, it has already cleaned up after itself.
device_unregister() would incorrectly call device_del() when
device_add() was never successful. Therefore, change both error paths
to use put_device() instead of device_unregister().

Found by code review.

Cc: stable@vger.kernel.org
Fixes: 53d2a715c240 ("phy: Add Tegra XUSB pad controller support")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
Changes in v2:
- modified the Fixes tag;
- modified the patch description.
---
 drivers/phy/tegra/xusb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index c89df95aa6ca..d89493d68699 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -171,16 +171,16 @@ int tegra_xusb_pad_init(struct tegra_xusb_pad *pad,
 
 	err = dev_set_name(&pad->dev, "%s", pad->soc->name);
 	if (err < 0)
-		goto unregister;
+		goto put_device;
 
 	err = device_add(&pad->dev);
 	if (err < 0)
-		goto unregister;
+		goto put_device;
 
 	return 0;
 
-unregister:
-	device_unregister(&pad->dev);
+put_device:
+	put_device(&pad->dev);
 	return err;
 }
 
-- 
2.17.1