[PATCH 5.12 632/677] net: phy: marvell: fix m88e1011_set_downshift

From: Greg Kroah-Hartman
Date: Wed May 12 2021 - 15:22:46 EST


From: Maxim Kochetkov <fido_max@xxxxxxxx>

[ Upstream commit 990875b299b8612aeb85cb2e2751796f1add65ff ]

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: 911af5e149bb ("net: phy: marvell: fix downshift function naming")
Signed-off-by: Maxim Kochetkov <fido_max@xxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/phy/marvell.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index 8018ddf7f316..723f25f6138d 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -1025,22 +1025,28 @@ static int m88e1011_get_downshift(struct phy_device *phydev, u8 *data)

static int m88e1011_set_downshift(struct phy_device *phydev, u8 cnt)
{
- int val;
+ int val, err;

if (cnt > MII_M1011_PHY_SCR_DOWNSHIFT_MAX)
return -E2BIG;

- if (!cnt)
- return phy_clear_bits(phydev, MII_M1011_PHY_SCR,
- MII_M1011_PHY_SCR_DOWNSHIFT_EN);
+ if (!cnt) {
+ err = phy_clear_bits(phydev, MII_M1011_PHY_SCR,
+ MII_M1011_PHY_SCR_DOWNSHIFT_EN);
+ } else {
+ val = MII_M1011_PHY_SCR_DOWNSHIFT_EN;
+ val |= FIELD_PREP(MII_M1011_PHY_SCR_DOWNSHIFT_MASK, cnt - 1);

- val = MII_M1011_PHY_SCR_DOWNSHIFT_EN;
- val |= FIELD_PREP(MII_M1011_PHY_SCR_DOWNSHIFT_MASK, cnt - 1);
+ err = phy_modify(phydev, MII_M1011_PHY_SCR,
+ MII_M1011_PHY_SCR_DOWNSHIFT_EN |
+ MII_M1011_PHY_SCR_DOWNSHIFT_MASK,
+ val);
+ }

- return phy_modify(phydev, MII_M1011_PHY_SCR,
- MII_M1011_PHY_SCR_DOWNSHIFT_EN |
- MII_M1011_PHY_SCR_DOWNSHIFT_MASK,
- val);
+ if (err < 0)
+ return err;
+
+ return genphy_soft_reset(phydev);
}

static int m88e1011_get_tunable(struct phy_device *phydev,
--
2.30.2