[PATCH 5.11 561/601] net: phy: marvell: fix m88e1111_set_downshift

Greg Kroah-Hartman
2021-05-12T18:06:42Z

From: Maxim Kochetkov <fido_max@inbox.ru>

[ 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>
---
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 04e7b9a7799c..47e5200eb039 100644
--- 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,
--
2.30.2