When tested the PHY SGMII Loopback: 1.set the LOOPBACK bit, 2.set the autoneg to AUTONEG_DISABLE, it calls the genphy_setup_forced which will clear the bit.
The BMCR_LOOPBACK bit should be preserved. As Florian pointed out that other bits should be preserved too. So I make the BMCR_ISOLATE and BMCR_PDOWN as well. Signed-off-by: Weidong Wang <wangweido...@huawei.com> --- the patch is evoluted from "phy: keep the BCMR_LOOPBACK bit while setup forced mode". --- drivers/net/phy/phy_device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index d551df6..9b24d7e 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -818,8 +818,9 @@ static int genphy_config_advert(struct phy_device *phydev) */ int genphy_setup_forced(struct phy_device *phydev) { - int ctl = 0; + int ctl = phy_read(phydev, MII_BMCR); + ctl &= BMCR_LOOPBACK | BMCR_ISOLATE | BMCR_PDOWN; phydev->pause = 0; phydev->asym_pause = 0; -- 2.7.0