diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h index 6f2887a5e0be..6159deab8c98 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h @@ -594,6 +594,7 @@ struct bcmgenet_priv { wait_queue_head_t wq; struct phy_device *phydev; struct device_node *phy_dn; + struct device_node *mdio_dn; struct mii_bus *mii_bus; u16 gphy_rev; struct clk *clk_eee; diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c index 6bef04e2f735..adf23d2ac488 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c @@ -408,6 +408,52 @@ static int bcmgenet_mii_probe(struct net_device *dev) return 0; } +/* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with + * their internal MDIO management controller making them fail to successfully + * be read from or written to for the first transaction. We insert a dummy + * BMSR read here to make sure that phy_get_device() and get_phy_id() can + * correctly read the PHY MII_PHYSID1/2 registers and successfully register a + * PHY device for this peripheral. + * + * Once the PHY driver is registered, we can workaround subsequent reads from + * there (e.g: during system-wide power management). + * + * bus->reset is invoked before mdiobus_scan during mdiobus_register and is + * therefore the right location to stick that workaround. Since we do not want + * to read from non-existing PHYs, we either use bus->phy_mask or do a manual + * Device Tree scan to limit the search area. + */ +static int bcmgenet_mii_bus_reset(struct mii_bus *bus) +{ + struct net_device *dev = bus->priv; + struct bcmgenet_priv *priv = netdev_priv(dev); + struct device_node *np = priv->mdio_dn; + struct device_node *child = NULL; + u32 read_mask = 0; + int addr = 0; + + if (!np) { + read_mask = 1 << priv->phy_addr; + } else { + for_each_available_child_of_node(np, child) { + addr = of_mdio_parse_addr(&dev->dev, child); + if (addr < 0) + continue; + + read_mask |= 1 << addr; + } + } + + for (addr = 0; addr < PHY_MAX_ADDR; addr++) { + if (read_mask & 1 << addr) { + dev_dbg(&dev->dev, "Workaround for PHY @ %d\n", addr); + mdiobus_read(bus, addr, MII_BMSR); + } + } + + return 0; +} + static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv) { struct mii_bus *bus; @@ -427,6 +473,7 @@ static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv) bus->parent = &priv->pdev->dev; bus->read = bcmgenet_mii_read; bus->write = bcmgenet_mii_write; + bus->reset = bcmgenet_mii_bus_reset; snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", priv->pdev->name, priv->pdev->id); @@ -443,7 +490,6 @@ static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv) { struct device_node *dn = priv->pdev->dev.of_node; struct device *kdev = &priv->pdev->dev; - struct device_node *mdio_dn; char *compat; int ret; @@ -451,14 +497,14 @@ static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv) if (!compat) return -ENOMEM; - mdio_dn = of_find_compatible_node(dn, NULL, compat); + priv->mdio_dn = of_find_compatible_node(dn, NULL, compat); kfree(compat); - if (!mdio_dn) { + if (!priv->mdio_dn) { dev_err(kdev, "unable to find MDIO bus node\n"); return -ENODEV; } - ret = of_mdiobus_register(priv->mii_bus, mdio_dn); + ret = of_mdiobus_register(priv->mii_bus, priv->mdio_dn); if (ret) { dev_err(kdev, "failed to register MDIO bus\n"); return ret;