net: phy: marvell: fix m88e1111_set_downshift

[ Upstream commit e7679c55a7249f1315256cfc672d53e84072e223 ]

Changing downshift params without software reset has no effect,
so call genphy_soft_reset() after change downshift params.

As the datasheet says:
Changes to these bits are disruptive to the normal operation therefore,
any changes to these registers must be followed by software reset
to take effect.

Fixes: 5c6bc5199b5d ("net: phy: marvell: add downshift support for M88E1111")
Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index 04e7b9a7799cf846b557774f620316ea56d6adb8..47e5200eb039fd26aaa80e8373dc436170483818 100644 (file)
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -964,22 +964,28 @@ static int m88e1111_get_downshift(struct phy_device *phydev, u8 *data)
 
 static int m88e1111_set_downshift(struct phy_device *phydev, u8 cnt)
 {
-       int val;
+       int val, err;
 
        if (cnt > MII_M1111_PHY_EXT_CR_DOWNSHIFT_MAX)
                return -E2BIG;
 
-       if (!cnt)
-               return phy_clear_bits(phydev, MII_M1111_PHY_EXT_CR,
-                                     MII_M1111_PHY_EXT_CR_DOWNSHIFT_EN);
+       if (!cnt) {
+               err = phy_clear_bits(phydev, MII_M1111_PHY_EXT_CR,
+                                    MII_M1111_PHY_EXT_CR_DOWNSHIFT_EN);
+       } else {
+               val = MII_M1111_PHY_EXT_CR_DOWNSHIFT_EN;
+               val |= FIELD_PREP(MII_M1111_PHY_EXT_CR_DOWNSHIFT_MASK, cnt - 1);
 
-       val = MII_M1111_PHY_EXT_CR_DOWNSHIFT_EN;
-       val |= FIELD_PREP(MII_M1111_PHY_EXT_CR_DOWNSHIFT_MASK, cnt - 1);
+               err = phy_modify(phydev, MII_M1111_PHY_EXT_CR,
+                                MII_M1111_PHY_EXT_CR_DOWNSHIFT_EN |
+                                MII_M1111_PHY_EXT_CR_DOWNSHIFT_MASK,
+                                val);
+       }
 
-       return phy_modify(phydev, MII_M1111_PHY_EXT_CR,
-                         MII_M1111_PHY_EXT_CR_DOWNSHIFT_EN |
-                         MII_M1111_PHY_EXT_CR_DOWNSHIFT_MASK,
-                         val);
+       if (err < 0)
+               return err;
+
+       return genphy_soft_reset(phydev);
 }
 
 static int m88e1111_get_tunable(struct phy_device *phydev,