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, 3 insertions, 2 deletions

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 554836edd915..5e43ae751412 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -88,7 +88,7 @@ struct mii_bus {
 
         /* A lock to ensure that only one thing can read/write
          * the MDIO bus at a time */
-        spinlock_t mdio_lock;
+        struct mutex mdio_lock;
 
         struct device *dev;
 
@@ -284,10 +284,11 @@ struct phy_device {
 
         /* Interrupt and Polling infrastructure */
         struct work_struct phy_queue;
+        struct work_struct state_queue;
         struct timer_list phy_timer;
         atomic_t irq_disable;
 
-        spinlock_t lock;
+        struct mutex lock;
 
         struct net_device *attached_dev;