From: Vladimir Oltean <vladimir.oltean@xxxxxxx> [ Upstream commit 0b5f0f29b118910c89fe249cdfbc11b400a86a18 ] The SJA1110 switch integrates TJA1103 PHYs, but in SJA1110 switch rev B silicon, there is a bug in that the registers for selecting the 100base-T1 autoneg master/slave roles are not writable. To enable write access to the master/slave registers, these additional PHY writes are necessary during initialization. The issue has been corrected in later SJA1110 silicon versions and is not present in the standalone PHY variants, but applying the workaround unconditionally in the driver should not do any harm. Suggested-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@xxxxxxxxxxx> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/phy/nxp-c45-tja11xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/phy/nxp-c45-tja11xx.c b/drivers/net/phy/nxp-c45-tja11xx.c index 26b9c0d7cb9d..b7ce0e737333 100644 --- a/drivers/net/phy/nxp-c45-tja11xx.c +++ b/drivers/net/phy/nxp-c45-tja11xx.c @@ -546,6 +546,12 @@ static int nxp_c45_config_init(struct phy_device *phydev) return ret; } + /* Bug workaround for SJA1110 rev B: enable write access + * to MDIO_MMD_PMAPMD + */ + phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x01F8, 1); + phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x01F9, 2); + phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, VEND1_PHY_CONFIG, PHY_CONFIG_AUTO); -- 2.30.2
