net: axienet: allow setups without MDIO

In setups with fixed-link settings there is no mdio node in DTS.
axienet_probe() already handles that gracefully but lp->mii_bus is
then NULL.

Fix code that tries to blindly grab the MDIO lock by introducing two helper
functions that make the locking conditional.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index 1e966a39967e5f8eb885c109d857be722158c343..aca7f82f6791b6f7551df1720b349e69af41e7cc 100644 (file)
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -504,6 +504,18 @@ static inline u32 axinet_ior_read_mcr(struct axienet_local *lp)
        return axienet_ior(lp, XAE_MDIO_MCR_OFFSET);
 }
 
+static inline void axienet_lock_mii(struct axienet_local *lp)
+{
+       if (lp->mii_bus)
+               mutex_lock(&lp->mii_bus->mdio_lock);
+}
+
+static inline void axienet_unlock_mii(struct axienet_local *lp)
+{
+       if (lp->mii_bus)
+               mutex_unlock(&lp->mii_bus->mdio_lock);
+}
+
 /**
  * axienet_iow - Memory mapped Axi Ethernet register write
  * @lp:         Pointer to axienet local structure

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 5d677db0aee5dd0c071a387a9a914d63e7c3cac1..f8f8654ea728c24dcefca36cdabfd0256ff6078b 100644 (file)
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -1053,9 +1053,9 @@ static int axienet_open(struct net_device *ndev)
         * including the MDIO. MDIO must be disabled before resetting.
         * Hold MDIO bus lock to avoid MDIO accesses during the reset.
         */
-       mutex_lock(&lp->mii_bus->mdio_lock);
+       axienet_lock_mii(lp);
        ret = axienet_device_reset(ndev);
-       mutex_unlock(&lp->mii_bus->mdio_lock);
+       axienet_unlock_mii(lp);
 
        ret = phylink_of_phy_connect(lp->phylink, lp->dev->of_node, 0);
        if (ret) {
@@ -1148,9 +1148,9 @@ static int axienet_stop(struct net_device *ndev)
        }
 
        /* Do a reset to ensure DMA is really stopped */
-       mutex_lock(&lp->mii_bus->mdio_lock);
+       axienet_lock_mii(lp);
        __axienet_device_reset(lp);
-       mutex_unlock(&lp->mii_bus->mdio_lock);
+       axienet_unlock_mii(lp);
 
        cancel_work_sync(&lp->dma_err_task);
 
@@ -1709,9 +1709,9 @@ static void axienet_dma_err_handler(struct work_struct *work)
         * including the MDIO. MDIO must be disabled before resetting.
         * Hold MDIO bus lock to avoid MDIO accesses during the reset.
         */
-       mutex_lock(&lp->mii_bus->mdio_lock);
+       axienet_lock_mii(lp);
        __axienet_device_reset(lp);
-       mutex_unlock(&lp->mii_bus->mdio_lock);
+       axienet_unlock_mii(lp);
 
        for (i = 0; i < lp->tx_bd_num; i++) {
                cur_p = &lp->tx_bd_v[i];