net: hns: Fix wrong read accesses via Clause 45 MDIO protocol

BugLink: https://bugs.launchpad.net/bugs/1822271

[ Upstream commit cec8abba ]

When reading phy registers via Clause 45 MDIO protocol, after write
address operation, the driver use another write address operation, so
can not read the right value of any phy registers. This patch fixes it.
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/net/ethernet/hisilicon/hns_mdio.c

@@ -319,7 +319,7 @@ static int hns_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 		}
 
 		hns_mdio_cmd_write(mdio_dev, is_c45,
-				   MDIO_C45_WRITE_ADDR, phy_id, devad);
+				   MDIO_C45_READ, phy_id, devad);
 	}
 
 	/* Step 5: waitting for MDIO_COMMAND_REG 's mdio_start==0,*/