[REGRESSION, BISECTED] Broken networking with net/phy/marvell

[Aaro Koskinen]

Hi,

When upgrading from v4.13 to v4.14-rc6 on OpenRD Client, the box loses
network connectivity.

Bisection points to:

commit 5987feb38aa55e035ce5376c02aba88a604cc881
Author: Dan Carpenter <dan.carpen...@oracle.com>
Date:   Fri Aug 4 11:17:21 2017 +0300

    net: phy: marvell: logical vs bitwise OR typo
    
However, it seems this commit just unhides another issue in the original
commit 864dc729d528 ("net: phy: marvell: Refactor m88e1121 RGMII delay
configuration"): when we are configuring the MSCR delay bits, we are
probably clearing the bits with a wrong mask (i.e. we might be disabling
something else not intended)...

I have tested the below change and it seems to fix the networking. Any
comments?

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index 15cbcdb..500d7c1 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -474,7 +474,7 @@ static int m88e1121_config_aneg_rgmii_delays(struct 
phy_device *phydev)
                goto out;
        }
 
-       mscr &= MII_88E1121_PHY_MSCR_DELAY_MASK;
+       mscr &= ~MII_88E1121_PHY_MSCR_DELAY_MASK;
 
        if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
                mscr |= (MII_88E1121_PHY_MSCR_RX_DELAY |

A.