diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 09096c3ceb86..8d9af2772853 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -661,6 +661,28 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, u32 phy_id, } EXPORT_SYMBOL(phy_device_create); +/* phy_c45_probe_present - checks to see if a MMD is present in the package + * @bus: the target MII bus + * @prtad: PHY package address on the MII bus + * @devad: PHY device (MMD) address + * + * Read the MDIO_STAT2 register, and check whether a device is responding + * at this address. + * + * Returns: negative error number on bus access error, zero if no device + * is responding, or positive if a device is present. + */ +static int phy_c45_probe_present(struct mii_bus *bus, int prtad, int devad) +{ + int stat2; + + stat2 = mdiobus_c45_read(bus, prtad, devad, MDIO_STAT2); + if (stat2 < 0) + return stat2; + + return (stat2 & MDIO_STAT2_DEVPRST) == MDIO_STAT2_DEVPRST_VAL; +} + /* get_phy_c45_devs_in_pkg - reads a MMD's devices in package registers. * @bus: the target MII bus * @addr: PHY address on the MII bus @@ -711,12 +733,26 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, { const int num_ids = ARRAY_SIZE(c45_ids->device_ids); u32 *devs = &c45_ids->devices_in_package; - int i, phy_reg; + int i, ret, phy_reg; /* Find first non-zero Devices In package. Device zero is reserved * for 802.3 c45 complied PHYs, so don't probe it at first. */ - for (i = 1; i < num_ids && *devs == 0; i++) { + for (i = 1; i < MDIO_MMD_NUM && *devs == 0; i++) { + if (i == MDIO_MMD_VEND1 || i == MDIO_MMD_VEND2) { + /* Check that there is a device present at this + * address before reading the devices-in-package + * register to avoid reading garbage from the PHY. + * Some PHYs (88x3310) vendor space is not IEEE802.3 + * compliant. + */ + ret = phy_c45_probe_present(bus, addr, i); + if (ret < 0) + return -EIO; + + if (!ret) + continue; + } phy_reg = get_phy_c45_devs_in_pkg(bus, addr, i, devs); if (phy_reg < 0) return -EIO; diff --git a/include/linux/phy.h b/include/linux/phy.h index 8c05d0fb5c00..abe318387331 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -388,6 +388,8 @@ enum phy_state { PHY_CABLETEST, }; +#define MDIO_MMD_NUM 32 + /** * struct phy_c45_device_ids - 802.3-c45 Device Identifiers * @devices_in_package: Bit vector of devices present.