PHYLIB: Locking fixes for PHY I/O potentially sleeping

PHY read/write functions can potentially sleep (e.g., a PHY accessed
via I2C).  The following changes were made to account for this:

    * Change spin locks to mutex locks
    * Add a BUG_ON() to phy_read() phy_write() to warn against
      calling them from an interrupt context.
    * Use work queue for PHY state machine handling since
      it can potentially sleep
    * Change phydev lock from spinlock to mutex

Signed-off-by: Nate Case <ncase@xes-inc.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 5b9e1751e1b..f4c4fd85425 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -25,7 +25,6 @@
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
-#include <linux/spinlock.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mii.h>
@@ -80,7 +79,7 @@ struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
 
 	dev->state = PHY_DOWN;
 
-	spin_lock_init(&dev->lock);
+	mutex_init(&dev->lock);
 
 	return dev;
 }
@@ -656,7 +655,7 @@ static int phy_probe(struct device *dev)
 	if (!(phydrv->flags & PHY_HAS_INTERRUPT))
 		phydev->irq = PHY_POLL;
 
-	spin_lock_bh(&phydev->lock);
+	mutex_lock(&phydev->lock);
 
 	/* Start out supporting everything. Eventually,
 	 * a controller will attach, and may modify one
@@ -670,7 +669,7 @@ static int phy_probe(struct device *dev)
 	if (phydev->drv->probe)
 		err = phydev->drv->probe(phydev);
 
-	spin_unlock_bh(&phydev->lock);
+	mutex_unlock(&phydev->lock);
 
 	return err;
 
@@ -682,9 +681,9 @@ static int phy_remove(struct device *dev)
 
 	phydev = to_phy_device(dev);
 
-	spin_lock_bh(&phydev->lock);
+	mutex_lock(&phydev->lock);
 	phydev->state = PHY_DOWN;
-	spin_unlock_bh(&phydev->lock);
+	mutex_unlock(&phydev->lock);
 
 	if (phydev->drv->remove)
 		phydev->drv->remove(phydev);