net: asix: Avoid looping when the device is disconnected

From: Vincent Palatin <vpalatin@chromium.org>

Check the answers from the USB stack and avoid re-sending multiple times
the request if the device has disappeared.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Tested-by: Robert Foss <robert.foss@collabora.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 46 insertions, 12 deletions

diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c
index 25609eefc762..f79eb12c326a 100644
--- a/drivers/net/usb/asix_common.c
+++ b/drivers/net/usb/asix_common.c
@@ -428,13 +428,21 @@ int asix_mdio_read(struct net_device *netdev, int phy_id, int loc)
         __le16 res;
         u8 smsr;
         int i = 0;
+        int ret;
 
         mutex_lock(&dev->phy_mutex);
         do {
-                asix_set_sw_mii(dev, 0);
+                ret = asix_set_sw_mii(dev, 0);
+                if (ret == -ENODEV)
+                        break;
                 usleep_range(1000, 1100);
-                asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 0);
-        } while (!(smsr & AX_HOST_EN) && (i++ < 30));
+                ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
+                                    0, 0, 1, &smsr, 0);
+        } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
+        if (ret == -ENODEV) {
+                mutex_unlock(&dev->phy_mutex);
+                return ret;
+        }
 
         asix_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id,
                                 (__u16)loc, 2, &res, 0);
@@ -453,16 +461,24 @@ void asix_mdio_write(struct net_device *netdev, int phy_id, int loc, int val)
         __le16 res = cpu_to_le16(val);
         u8 smsr;
         int i = 0;
+        int ret;
 
         netdev_dbg(dev->net, "asix_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x\n",
                         phy_id, loc, val);
 
         mutex_lock(&dev->phy_mutex);
         do {
-                asix_set_sw_mii(dev, 0);
+                ret = asix_set_sw_mii(dev, 0);
+                if (ret == -ENODEV)
+                        break;
                 usleep_range(1000, 1100);
-                asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 0);
-        } while (!(smsr & AX_HOST_EN) && (i++ < 30));
+                ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
+                                    0, 0, 1, &smsr, 0);
+        } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
+        if (ret == -ENODEV) {
+                mutex_unlock(&dev->phy_mutex);
+                return;
+        }
 
         asix_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id,
                        (__u16)loc, 2, &res, 0);
@@ -476,13 +492,21 @@ int asix_mdio_read_nopm(struct net_device *netdev, int phy_id, int loc)
         __le16 res;
         u8 smsr;
         int i = 0;
+        int ret;
 
         mutex_lock(&dev->phy_mutex);
         do {
-                asix_set_sw_mii(dev, 1);
+                ret = asix_set_sw_mii(dev, 1);
+                if (ret == -ENODEV)
+                        break;
                 usleep_range(1000, 1100);
-                asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 1);
-        } while (!(smsr & AX_HOST_EN) && (i++ < 30));
+                ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
+                                    0, 0, 1, &smsr, 1);
+        } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
+        if (ret == -ENODEV) {
+                mutex_unlock(&dev->phy_mutex);
+                return ret;
+        }
 
         asix_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id,
                       (__u16)loc, 2, &res, 1);
@@ -502,16 +526,24 @@ asix_mdio_write_nopm(struct net_device *netdev, int phy_id, int loc, int val)
         __le16 res = cpu_to_le16(val);
         u8 smsr;
         int i = 0;
+        int ret;
 
         netdev_dbg(dev->net, "asix_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x\n",
                         phy_id, loc, val);
 
         mutex_lock(&dev->phy_mutex);
         do {
-                asix_set_sw_mii(dev, 1);
+                ret = asix_set_sw_mii(dev, 1);
+                if (ret == -ENODEV)
+                        break;
                 usleep_range(1000, 1100);
-                asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG, 0, 0, 1, &smsr, 1);
-        } while (!(smsr & AX_HOST_EN) && (i++ < 30));
+                ret = asix_read_cmd(dev, AX_CMD_STATMNGSTS_REG,
+                                    0, 0, 1, &smsr, 1);
+        } while (!(smsr & AX_HOST_EN) && (i++ < 30) && (ret != -ENODEV));
+        if (ret == -ENODEV) {
+                mutex_unlock(&dev->phy_mutex);
+                return;
+        }
 
         asix_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id,
                        (__u16)loc, 2, &res, 1);
diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index aaa42909d932..ebeb73014fdf 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -79,6 +79,8 @@ static u32 asix_get_phyid(struct usbnet *dev)
         /* Poll for the rare case the FW or phy isn't ready yet.  */
         for (i = 0; i < 100; i++) {
                 phy_reg = asix_mdio_read(dev->net, dev->mii.phy_id, MII_PHYSID1);
+                if (phy_reg < 0)
+                        return 0;
                 if (phy_reg != 0 && phy_reg != 0xFFFF)
                         break;
                 mdelay(1);