From: Alexandre Messier amessier@tycoint.com
Micrel PHYs KSZ8021/31 and KSZ8081 have a feature where MDIO address 0 is considered as a broadcast address; the PHY will respond even if it is not its configured (pinstrapped) address. This feature is enabled by default.
The Linux kernel disables that feature at initialisation, but not before it probes the MDIO bus. This causes an issue, because a PHY at address 3 will be discovered at addresses 0 and 3, but will then only respond at address 3. Because Linux attaches the first PHY it discovers on 'eth0', it will attach the PHY from address 0, which will never answer again.
Fix the issue by disabling the broadcast feature in U-Boot, before Linux is started.
Signed-off-by: Alexandre Messier amessier@tycoint.com --- drivers/net/phy/micrel.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index cbec928..2458254 100644 --- a/drivers/net/phy/micrel.c +++ b/drivers/net/phy/micrel.c @@ -22,12 +22,30 @@ static struct phy_driver KSZ804_driver = { .shutdown = &genphy_shutdown, };
+#define MII_KSZPHY_OMSO 0x16 +#define KSZPHY_OMSO_B_CAST_OFF (1 << 9) + +static int ksz_genconfig_bcastoff(struct phy_device *phydev) +{ + int ret; + + ret = phy_read(phydev, MDIO_DEVAD_NONE, MII_KSZPHY_OMSO); + if (ret < 0) + return ret; + + ret = phy_write(phydev, MDIO_DEVAD_NONE, MII_KSZPHY_OMSO, ret | KSZPHY_OMSO_B_CAST_OFF); + if (ret < 0) + return ret; + + return genphy_config(phydev); +} + static struct phy_driver KSZ8031_driver = { .name = "Micrel KSZ8021/KSZ8031", .uid = 0x221550, .mask = 0xfffff0, .features = PHY_BASIC_FEATURES, - .config = &genphy_config, + .config = &ksz_genconfig_bcastoff, .startup = &genphy_startup, .shutdown = &genphy_shutdown, }; @@ -37,7 +55,7 @@ static struct phy_driver KSZ8081_driver = { .uid = 0x221560, .mask = 0xfffff0, .features = PHY_BASIC_FEATURES, - .config = &genphy_config, + .config = &ksz_genconfig_bcastoff, .startup = &genphy_startup, .shutdown = &genphy_shutdown, };