[PATCH 4.4 56/62] ravb: Fixed to be able to unload modules

Greg Kroah-Hartman
2020-09-11T17:29:11Z

From: Yuusuke Ashizuka <ashiduka@fujitsu.com>

commit 1838d6c62f57836639bd3d83e7855e0ee4f6defc upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/ethernet/renesas/ravb_main.c | 110 +++++++++++++++----------------
1 file changed, 55 insertions(+), 55 deletions(-)

--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1214,12 +1214,64 @@ static const struct ethtool_ops ravb_eth
.get_ts_info = ravb_get_ts_info,
};

+/* 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)
{
struct ravb_private *priv = netdev_priv(ndev);
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]);

@@ -1268,6 +1320,7 @@ out_free_irq:
out_napi_off:
napi_disable(&priv->napi[RAVB_NC]);
napi_disable(&priv->napi[RAVB_BE]);
+ ravb_mdio_release(priv);
return error;
}

@@ -1561,6 +1614,8 @@ static int ravb_close(struct net_device
ravb_ring_free(ndev, RAVB_BE);
ravb_ring_free(ndev, RAVB_NC);

+ ravb_mdio_release(priv);
+
return 0;
}

@@ -1664,51 +1719,6 @@ static const struct net_device_ops ravb_
.ndo_change_mtu = eth_change_mtu,
};

-/* 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 },
@@ -1847,13 +1857,6 @@ static int ravb_probe(struct platform_de
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);

@@ -1873,8 +1876,6 @@ static int ravb_probe(struct platform_de
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);
out_release:
@@ -1899,7 +1900,6 @@ static int ravb_remove(struct platform_d
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);