From 5f6c99e0ab805d8ec9eda105822912d49aa1d409 Mon Sep 17 00:00:00 2001 From: Shaohui Xie Date: Tue, 3 Nov 2015 12:27:33 +0800 Subject: [PATCH] net: phy: fix a bug in get_phy_c45_ids When probing devices-in-package for a c45 phy, device zero is the last device to probe, however, if driver reads 0 from device zero, c45_ids->devices_in_package is set to '0', the loop condition of probing will be matched again, see codes below: for (i = 1;i < num_ids && c45_ids->devices_in_package == 0;i++) driver will run in a dead loop. This patch restructures the bug and confusing loop, it provides a helper function get_phy_c45_devs_in_pkg which to read devices-in-package registers of a MMD, and rewrites the loop with using the helper function. Signed-off-by: Shaohui Xie Signed-off-by: David S. Miller --- drivers/net/phy/phy_device.c | 74 ++++++++++++++++++++++++------------ 1 file changed, 49 insertions(+), 25 deletions(-) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index f761288abe66..0a76cc5d13da 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -205,6 +205,37 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id, } EXPORT_SYMBOL(phy_device_create); +/* 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 + * @dev_addr: MMD address in the PHY. + * @devices_in_package: where to store the devices in package information. + * + * Description: reads devices in package registers of a MMD at @dev_addr + * from PHY at @addr on @bus. + * + * Returns: 0 on success, -EIO on failure. + */ +static int get_phy_c45_devs_in_pkg(struct mii_bus *bus, int addr, int dev_addr, + u32 *devices_in_package) +{ + int phy_reg, reg_addr; + + reg_addr = MII_ADDR_C45 | dev_addr << 16 | MDIO_DEVS2; + phy_reg = mdiobus_read(bus, addr, reg_addr); + if (phy_reg < 0) + return -EIO; + *devices_in_package = (phy_reg & 0xffff) << 16; + + reg_addr = MII_ADDR_C45 | dev_addr << 16 | MDIO_DEVS1; + phy_reg = mdiobus_read(bus, addr, reg_addr); + if (phy_reg < 0) + return -EIO; + *devices_in_package |= (phy_reg & 0xffff); + + return 0; +} + /** * get_phy_c45_ids - reads the specified addr for its 802.3-c45 IDs. * @bus: the target MII bus @@ -223,38 +254,31 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, int phy_reg; int i, reg_addr; const int num_ids = ARRAY_SIZE(c45_ids->device_ids); + u32 *devs = &c45_ids->devices_in_package; - /* Find first non-zero Devices In package. Device - * zero is reserved, so don't probe it. + /* 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 && c45_ids->devices_in_package == 0; - i++) { -retry: reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS2; - phy_reg = mdiobus_read(bus, addr, reg_addr); + for (i = 1; i < num_ids && *devs == 0; i++) { + phy_reg = get_phy_c45_devs_in_pkg(bus, addr, i, devs); if (phy_reg < 0) return -EIO; - c45_ids->devices_in_package = (phy_reg & 0xffff) << 16; - reg_addr = MII_ADDR_C45 | i << 16 | MDIO_DEVS1; - phy_reg = mdiobus_read(bus, addr, reg_addr); - if (phy_reg < 0) - return -EIO; - c45_ids->devices_in_package |= (phy_reg & 0xffff); - - if ((c45_ids->devices_in_package & 0x1fffffff) == 0x1fffffff) { - if (i) { - /* If mostly Fs, there is no device there, - * then let's continue to probe more, as some - * 10G PHYs have zero Devices In package, - * e.g. Cortina CS4315/CS4340 PHY. - */ - i = 0; - goto retry; - } else { - /* no device there, let's get out of here */ + if ((*devs & 0x1fffffff) == 0x1fffffff) { + /* If mostly Fs, there is no device there, + * then let's continue to probe more, as some + * 10G PHYs have zero Devices In package, + * e.g. Cortina CS4315/CS4340 PHY. + */ + phy_reg = get_phy_c45_devs_in_pkg(bus, addr, 0, devs); + if (phy_reg < 0) + return -EIO; + /* no device there, let's get out of here */ + if ((*devs & 0x1fffffff) == 0x1fffffff) { *phy_id = 0xffffffff; return 0; + } else { + break; } } } -- 2.30.2