smsc95xx: Ignore -ENODEV errors when device is unplugged

[ Upstream commit c70c453abcbf3ecbaadd4c3236a5119b8da365cf ]

According to Documentation/driver-api/usb/URB.rst when a device
is unplugged usb_submit_urb() returns -ENODEV.

This error code propagates all the way up to usbnet_read_cmd() and
usbnet_write_cmd() calls inside the smsc95xx.c driver during
Ethernet cable unplug, unbind or reboot.

This causes the following errors to be shown on reboot, for example:

ci_hdrc ci_hdrc.1: remove, state 1
usb usb2: USB disconnect, device number 1
usb 2-1: USB disconnect, device number 2
usb 2-1.1: USB disconnect, device number 3
smsc95xx 2-1.1:1.0 eth1: unregister 'smsc95xx' usb-ci_hdrc.1-1.1, smsc95xx USB 2.0 Ethernet
smsc95xx 2-1.1:1.0 eth1: Failed to read reg index 0x00000114: -19
smsc95xx 2-1.1:1.0 eth1: Error reading MII_ACCESS
smsc95xx 2-1.1:1.0 eth1: __smsc95xx_mdio_read: MII is busy
smsc95xx 2-1.1:1.0 eth1: Failed to read reg index 0x00000114: -19
smsc95xx 2-1.1:1.0 eth1: Error reading MII_ACCESS
smsc95xx 2-1.1:1.0 eth1: __smsc95xx_mdio_read: MII is busy
smsc95xx 2-1.1:1.0 eth1: hardware isn't capable of remote wakeup
usb 2-1.4: USB disconnect, device number 4
ci_hdrc ci_hdrc.1: USB bus 2 deregistered
ci_hdrc ci_hdrc.0: remove, state 4
usb usb1: USB disconnect, device number 1
ci_hdrc ci_hdrc.0: USB bus 1 deregistered
imx2-wdt 30280000.watchdog: Device shutdown: Expect reboot!
reboot: Restarting system

Ignore the -ENODEV errors inside __smsc95xx_mdio_read() and
__smsc95xx_phy_wait_not_busy() and do not print error messages
when -ENODEV is returned.

Fixes: a049a30fc27c ("net: usb: Correct PHY handling of smsc95xx")
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 026e748..eb0d325 100644 (file)
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -84,9 +84,10 @@ static int __must_check __smsc95xx_read_reg(struct usbnet *dev, u32 index,
        ret = fn(dev, USB_VENDOR_REQUEST_READ_REGISTER, USB_DIR_IN
                 | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                 0, index, &buf, 4);
-       if (unlikely(ret < 0)) {
-               netdev_warn(dev->net, "Failed to read reg index 0x%08x: %d\n",
-                           index, ret);
+       if (ret < 0) {
+               if (ret != -ENODEV)
+                       netdev_warn(dev->net, "Failed to read reg index 0x%08x: %d\n",
+                                   index, ret);
                return ret;
        }
 
@@ -116,7 +117,7 @@ static int __must_check __smsc95xx_write_reg(struct usbnet *dev, u32 index,
        ret = fn(dev, USB_VENDOR_REQUEST_WRITE_REGISTER, USB_DIR_OUT
                 | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                 0, index, &buf, 4);
-       if (unlikely(ret < 0))
+       if (ret < 0 && ret != -ENODEV)
                netdev_warn(dev->net, "Failed to write reg index 0x%08x: %d\n",
                            index, ret);
 
@@ -159,6 +160,9 @@ static int __must_check __smsc95xx_phy_wait_not_busy(struct usbnet *dev,
        do {
                ret = __smsc95xx_read_reg(dev, MII_ADDR, &val, in_pm);
                if (ret < 0) {
+                       /* Ignore -ENODEV error during disconnect() */
+                       if (ret == -ENODEV)
+                               return 0;
                        netdev_warn(dev->net, "Error reading MII_ACCESS\n");
                        return ret;
                }
@@ -194,7 +198,8 @@ static int __smsc95xx_mdio_read(struct usbnet *dev, int phy_id, int idx,
        addr = mii_address_cmd(phy_id, idx, MII_READ_ | MII_BUSY_);
        ret = __smsc95xx_write_reg(dev, MII_ADDR, addr, in_pm);
        if (ret < 0) {
-               netdev_warn(dev->net, "Error writing MII_ADDR\n");
+               if (ret != -ENODEV)
+                       netdev_warn(dev->net, "Error writing MII_ADDR\n");
                goto done;
        }
 
@@ -206,7 +211,8 @@ static int __smsc95xx_mdio_read(struct usbnet *dev, int phy_id, int idx,
 
        ret = __smsc95xx_read_reg(dev, MII_DATA, &val, in_pm);
        if (ret < 0) {
-               netdev_warn(dev->net, "Error reading MII_DATA\n");
+               if (ret != -ENODEV)
+                       netdev_warn(dev->net, "Error reading MII_DATA\n");
                goto done;
        }
 
@@ -214,6 +220,10 @@ static int __smsc95xx_mdio_read(struct usbnet *dev, int phy_id, int idx,
 
 done:
        mutex_unlock(&dev->phy_mutex);
+
+       /* Ignore -ENODEV error during disconnect() */
+       if (ret == -ENODEV)
+               return 0;
        return ret;
 }
 
@@ -235,7 +245,8 @@ static void __smsc95xx_mdio_write(struct usbnet *dev, int phy_id,
        val = regval;
        ret = __smsc95xx_write_reg(dev, MII_DATA, val, in_pm);
        if (ret < 0) {
-               netdev_warn(dev->net, "Error writing MII_DATA\n");
+               if (ret != -ENODEV)
+                       netdev_warn(dev->net, "Error writing MII_DATA\n");
                goto done;
        }
 
@@ -243,7 +254,8 @@ static void __smsc95xx_mdio_write(struct usbnet *dev, int phy_id,
        addr = mii_address_cmd(phy_id, idx, MII_WRITE_ | MII_BUSY_);
        ret = __smsc95xx_write_reg(dev, MII_ADDR, addr, in_pm);
        if (ret < 0) {
-               netdev_warn(dev->net, "Error writing MII_ADDR\n");
+               if (ret != -ENODEV)
+                       netdev_warn(dev->net, "Error writing MII_ADDR\n");
                goto done;
        }