[PATCH AUTOSEL 4.19 56/59] net: usb: lan78xx: Connect PHY before registering MAC

Sasha Levin
2019-10-26T13:28:07Z

From: Andrew Lunn <andrew@lunn.ch>

[ Upstream commit 38b4fe320119859c11b1dc06f6b4987a16344fa1 ]

As soon as the netdev is registers, the kernel can start using the
interface. If the driver connects the MAC to the PHY after the netdev
is registered, there is a race condition where the interface can be
opened without having the PHY connected.

Change the order to close this race condition.

Fixes: 92571a1aae40 ("lan78xx: Connect phy early")
Reported-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/lan78xx.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index e20266bd209e2..06d2499ba127c 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -3796,10 +3796,14 @@ static int lan78xx_probe(struct usb_interface *intf,
/* driver requires remote-wakeup capability during autosuspend. */
intf->needs_remote_wakeup = 1;

+ ret = lan78xx_phy_init(dev);
+ if (ret < 0)
+ goto out4;
+
ret = register_netdev(netdev);
if (ret != 0) {
netif_err(dev, probe, netdev, "couldn't register the device\n");
- goto out4;
+ goto out5;
}

usb_set_intfdata(intf, dev);
@@ -3812,14 +3816,10 @@ static int lan78xx_probe(struct usb_interface *intf,
pm_runtime_set_autosuspend_delay(&udev->dev,
DEFAULT_AUTOSUSPEND_DELAY);

- ret = lan78xx_phy_init(dev);
- if (ret < 0)
- goto out5;
-
return 0;

out5:
- unregister_netdev(netdev);
+ phy_disconnect(netdev->phydev);
out4:
usb_free_urb(dev->urb_intr);
out3:
--
2.20.1