usbnet: add a mutex around phy register access
When working on the mcs7830, I noticed the need for a mutex in its
mdio_read/mdio_write functions. A related problem seems to be present
in the asix driver in the respective functions.
This introduces a mutex in the common usbnet driver and uses it
from the two hardware specific drivers.
Acked-by: David Hollis <dhollis@davehollis.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/net/asix.c b/drivers/usb/net/asix.c
index 5edd053..881841e 100644
--- a/drivers/usb/net/asix.c
+++ b/drivers/usb/net/asix.c
@@ -569,10 +569,12 @@
struct usbnet *dev = netdev_priv(netdev);
u16 res;
+ mutex_lock(&dev->phy_mutex);
asix_set_sw_mii(dev);
asix_read_cmd(dev, AX_CMD_READ_MII_REG, phy_id,
(__u16)loc, 2, (u16 *)&res);
asix_set_hw_mii(dev);
+ mutex_unlock(&dev->phy_mutex);
devdbg(dev, "asix_mdio_read() phy_id=0x%02x, loc=0x%02x, returns=0x%04x", phy_id, loc, le16_to_cpu(res & 0xffff));
@@ -586,10 +588,12 @@
u16 res = cpu_to_le16(val);
devdbg(dev, "asix_mdio_write() phy_id=0x%02x, loc=0x%02x, val=0x%04x", phy_id, loc, val);
+ mutex_lock(&dev->phy_mutex);
asix_set_sw_mii(dev);
asix_write_cmd(dev, AX_CMD_WRITE_MII_REG, phy_id,
(__u16)loc, 2, (u16 *)&res);
asix_set_hw_mii(dev);
+ mutex_unlock(&dev->phy_mutex);
}
/* Get the PHY Identifier from the PHYSID1 & PHYSID2 MII registers */
diff --git a/drivers/usb/net/mcs7830.c b/drivers/usb/net/mcs7830.c
index 23a8066..6240b97 100644
--- a/drivers/usb/net/mcs7830.c
+++ b/drivers/usb/net/mcs7830.c
@@ -184,6 +184,7 @@
HIF_REG_PHY_CMD2_PEND_FLAG_BIT | index,
};
+ mutex_lock(&dev->phy_mutex);
/* write the MII command */
ret = mcs7830_set_reg(dev, HIF_REG_PHY_CMD1, 2, cmd);
if (ret < 0)
@@ -208,6 +209,7 @@
dev_dbg(&dev->udev->dev, "read PHY reg %02x: %04x (%d tries)\n",
index, val, i);
out:
+ mutex_unlock(&dev->phy_mutex);
return ret;
}
@@ -222,6 +224,8 @@
HIF_REG_PHY_CMD2_PEND_FLAG_BIT | (index & 0x1F),
};
+ mutex_lock(&dev->phy_mutex);
+
/* write the new register contents */
le_val = cpu_to_le16(val);
ret = mcs7830_set_reg(dev, HIF_REG_PHY_DATA, 2, &le_val);
@@ -248,6 +252,7 @@
dev_dbg(&dev->udev->dev, "write PHY reg %02x: %04x (%d tries)\n",
index, val, i);
out:
+ mutex_unlock(&dev->phy_mutex);
return ret;
}
diff --git a/drivers/usb/net/usbnet.c b/drivers/usb/net/usbnet.c
index decc1b1..cf3d20e 100644
--- a/drivers/usb/net/usbnet.c
+++ b/drivers/usb/net/usbnet.c
@@ -1144,6 +1144,7 @@
dev->delay.function = usbnet_bh;
dev->delay.data = (unsigned long) dev;
init_timer (&dev->delay);
+ mutex_init (&dev->phy_mutex);
SET_MODULE_OWNER (net);
dev->net = net;
diff --git a/drivers/usb/net/usbnet.h b/drivers/usb/net/usbnet.h
index 743947c..07c70ab 100644
--- a/drivers/usb/net/usbnet.h
+++ b/drivers/usb/net/usbnet.h
@@ -30,6 +30,7 @@
struct usb_device *udev;
struct driver_info *driver_info;
wait_queue_head_t *wait;
+ struct mutex phy_mutex;
/* i/o info: pipes etc */
unsigned in, out;