[PATCH AUTOSEL 4.9 21/27] net: usb: asix: ax88772_bind return error when hw_reset fail

[Sasha Levin]

From: Zhang Run <zhang.run@xxxxxxxxxx>

[ Upstream commit 6eea3527e68acc22483f4763c8682f223eb90029 ]

The ax88772_bind() should return error code immediately when the PHY
was not reset properly through ax88772a_hw_reset().
Otherwise, The asix_get_phyid() will block when get the PHY
Identifier from the PHYSID1 MII registers through asix_mdio_read()
due to the PHY isn't ready. Furthermore, it will produce a lot of
error message cause system crash.As follows:
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to write
 reg index 0x0000: -71
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to send
 software reset: ffffffb9
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to write
 reg index 0x0000: -71
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to enable
 software MII access
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to read
 reg index 0x0000: -71
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to write
 reg index 0x0000: -71
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to enable
 software MII access
asix 1-1:1.0 (unnamed net_device) (uninitialized): Failed to read
 reg index 0x0000: -71
...

Signed-off-by: Zhang Run <zhang.run@xxxxxxxxxx>
Reviewed-by: Yang Wei <yang.wei9@xxxxxxxxxx>
Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/usb/asix_devices.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 5be6b67492d5..393fd3ed6b94 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -729,8 +729,13 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
 	asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &chipcode, 0);
 	chipcode &= AX_CHIPCODE_MASK;
 
-	(chipcode == AX_AX88772_CHIPCODE) ? ax88772_hw_reset(dev, 0) :
-					    ax88772a_hw_reset(dev, 0);
+	ret = (chipcode == AX_AX88772_CHIPCODE) ? ax88772_hw_reset(dev, 0) :
+						  ax88772a_hw_reset(dev, 0);
+
+	if (ret < 0) {
+		netdev_dbg(dev->net, "Failed to reset AX88772: %d\n", ret);
+		return ret;
+	}
 
 	/* Read PHYID register *AFTER* the PHY was reset properly */
 	phyid = asix_get_phyid(dev);
-- 
2.19.1