Messages in this thread Patch in this message | | | From | Hansen Yang <> | Subject | [PATCH] net: phy: marvell: Fix bits clear bug | Date | Sat, 2 Nov 2019 22:15:08 +0800 |
| |
The correct way to clear bits before setting some of them is using "& = ~BIT_MASK". The wrong operation "& = BIT_MASK" will clear other bits.
m88e1116r_config_init() calls marvell_set_polarity() to config MDI crossover mode by modifying reg MII_M1011_PHY_SCR, then it calls marvell_set_downshift() to config downshift by modifying the same reg. According to the bug, marvell_set_downshift() clears other bits and set MDI Crossover Mode to Manual MDI configuration. If we connect two devices both using this driver with a wrong Ethernet cable, they can't automatically adjust their crossover mode. Finally they fail to link.
Signed-off-by: Hansen Yang <yanghansen1@163.com> --- drivers/net/phy/marvell.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c index a7796134e3be..6ab8fe339043 100644 --- a/drivers/net/phy/marvell.c +++ b/drivers/net/phy/marvell.c @@ -282,7 +282,7 @@ static int marvell_set_downshift(struct phy_device *phydev, bool enable, if (reg < 0) return reg; - reg &= MII_M1011_PHY_SRC_DOWNSHIFT_MASK; + reg &= ~MII_M1011_PHY_SRC_DOWNSHIFT_MASK; reg |= ((retries - 1) << MII_M1011_PHY_SCR_DOWNSHIFT_SHIFT); if (enable) reg |= MII_M1011_PHY_SCR_DOWNSHIFT_EN; -- 2.17.1
| |