tree 9db641e98629cd41e1084a2d46417f720a06e035
parent 4e811b1e11d5bc9e25ca1a30ce6654add2b571e3
author wangweidong <wangweidong1@huawei.com> 1460619832 +0800
committer David S. Miller <davem@davemloft.net> 1460765400 -0400

phy: make some bits preserved while setup forced mode

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 <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>