ravb: Fixed to be able to unload modules

When this driver is built as a module, I cannot rmmod it after insmoding
it.
This is because that this driver calls ravb_mdio_init() at the time of
probe, and module->refcnt is incremented by alloc_mdio_bitbang() called
after that.
Therefore, even if ifup is not performed, the driver is in use and rmmod
cannot be performed.

$ lsmod
Module                  Size  Used by
ravb                   40960  1
$ rmmod ravb
rmmod: ERROR: Module ravb is in use

Call ravb_mdio_init() at open and free_mdio_bitbang() at close, thereby
rmmod is possible in the ifdown state.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Yuusuke Ashizuka <ashiduka@fujitsu.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 99f7aae..df89d09 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1342,6 +1342,51 @@ static inline int ravb_hook_irq(unsigned int irq, irq_handler_t handler,
        return error;
 }
 
+/* MDIO bus init function */
+static int ravb_mdio_init(struct ravb_private *priv)
+{
+       struct platform_device *pdev = priv->pdev;
+       struct device *dev = &pdev->dev;
+       int error;
+
+       /* Bitbang init */
+       priv->mdiobb.ops = &bb_ops;
+
+       /* MII controller setting */
+       priv->mii_bus = alloc_mdio_bitbang(&priv->mdiobb);
+       if (!priv->mii_bus)
+               return -ENOMEM;
+
+       /* Hook up MII support for ethtool */
+       priv->mii_bus->name = "ravb_mii";
+       priv->mii_bus->parent = dev;
+       snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
+                pdev->name, pdev->id);
+
+       /* Register MDIO bus */
+       error = of_mdiobus_register(priv->mii_bus, dev->of_node);
+       if (error)
+               goto out_free_bus;
+
+       return 0;
+
+out_free_bus:
+       free_mdio_bitbang(priv->mii_bus);
+       return error;
+}
+
+/* MDIO bus release function */
+static int ravb_mdio_release(struct ravb_private *priv)
+{
+       /* Unregister mdio bus */
+       mdiobus_unregister(priv->mii_bus);
+
+       /* Free bitbang info */
+       free_mdio_bitbang(priv->mii_bus);
+
+       return 0;
+}
+
 /* Network device open function for Ethernet AVB */
 static int ravb_open(struct net_device *ndev)
 {
@@ -1350,6 +1395,13 @@ static int ravb_open(struct net_device *ndev)
        struct device *dev = &pdev->dev;
        int error;
 
+       /* MDIO bus init */
+       error = ravb_mdio_init(priv);
+       if (error) {
+               netdev_err(ndev, "failed to initialize MDIO\n");
+               return error;
+       }
+
        napi_enable(&priv->napi[RAVB_BE]);
        napi_enable(&priv->napi[RAVB_NC]);
 
@@ -1427,6 +1479,7 @@ out_free_irq:
 out_napi_off:
        napi_disable(&priv->napi[RAVB_NC]);
        napi_disable(&priv->napi[RAVB_BE]);
+       ravb_mdio_release(priv);
        return error;
 }
 
@@ -1736,6 +1789,8 @@ static int ravb_close(struct net_device *ndev)
        ravb_ring_free(ndev, RAVB_BE);
        ravb_ring_free(ndev, RAVB_NC);
 
+       ravb_mdio_release(priv);
+
        return 0;
 }
 
@@ -1887,51 +1942,6 @@ static const struct net_device_ops ravb_netdev_ops = {
        .ndo_set_features       = ravb_set_features,
 };
 
-/* MDIO bus init function */
-static int ravb_mdio_init(struct ravb_private *priv)
-{
-       struct platform_device *pdev = priv->pdev;
-       struct device *dev = &pdev->dev;
-       int error;
-
-       /* Bitbang init */
-       priv->mdiobb.ops = &bb_ops;
-
-       /* MII controller setting */
-       priv->mii_bus = alloc_mdio_bitbang(&priv->mdiobb);
-       if (!priv->mii_bus)
-               return -ENOMEM;
-
-       /* Hook up MII support for ethtool */
-       priv->mii_bus->name = "ravb_mii";
-       priv->mii_bus->parent = dev;
-       snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
-                pdev->name, pdev->id);
-
-       /* Register MDIO bus */
-       error = of_mdiobus_register(priv->mii_bus, dev->of_node);
-       if (error)
-               goto out_free_bus;
-
-       return 0;
-
-out_free_bus:
-       free_mdio_bitbang(priv->mii_bus);
-       return error;
-}
-
-/* MDIO bus release function */
-static int ravb_mdio_release(struct ravb_private *priv)
-{
-       /* Unregister mdio bus */
-       mdiobus_unregister(priv->mii_bus);
-
-       /* Free bitbang info */
-       free_mdio_bitbang(priv->mii_bus);
-
-       return 0;
-}
-
 static const struct of_device_id ravb_match_table[] = {
        { .compatible = "renesas,etheravb-r8a7790", .data = (void *)RCAR_GEN2 },
        { .compatible = "renesas,etheravb-r8a7794", .data = (void *)RCAR_GEN2 },
@@ -2174,13 +2184,6 @@ static int ravb_probe(struct platform_device *pdev)
                eth_hw_addr_random(ndev);
        }
 
-       /* MDIO bus init */
-       error = ravb_mdio_init(priv);
-       if (error) {
-               dev_err(&pdev->dev, "failed to initialize MDIO\n");
-               goto out_dma_free;
-       }
-
        netif_napi_add(ndev, &priv->napi[RAVB_BE], ravb_poll, 64);
        netif_napi_add(ndev, &priv->napi[RAVB_NC], ravb_poll, 64);
 
@@ -2202,8 +2205,6 @@ static int ravb_probe(struct platform_device *pdev)
 out_napi_del:
        netif_napi_del(&priv->napi[RAVB_NC]);
        netif_napi_del(&priv->napi[RAVB_BE]);
-       ravb_mdio_release(priv);
-out_dma_free:
        dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,
                          priv->desc_bat_dma);
 
@@ -2235,7 +2236,6 @@ static int ravb_remove(struct platform_device *pdev)
        unregister_netdev(ndev);
        netif_napi_del(&priv->napi[RAVB_NC]);
        netif_napi_del(&priv->napi[RAVB_BE]);
-       ravb_mdio_release(priv);
        pm_runtime_disable(&pdev->dev);
        free_netdev(ndev);
        platform_set_drvdata(pdev, NULL);