From: David Thompson <davthompson@xxxxxxxxxx> [ Upstream commit 182447b12144b7be9b63a273d27c5a11bd54960a ] The MDIO gateway (GW) lock in BlueField-2 GIGE logic is set after read. This patch adds logic to make sure the lock is always cleared at the end of each MDIO transaction. Fixes: f92e1869d74e ("Add Mellanox BlueField Gigabit Ethernet driver") Reviewed-by: Asmaa Mnebhi <asmaa@xxxxxxxxxx> Signed-off-by: David Thompson <davthompson@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220902164247.19862-1-davthompson@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c index f979ba7e5eff..caa4380ada13 100644 --- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c @@ -178,6 +178,9 @@ static int mlxbf_gige_mdio_read(struct mii_bus *bus, int phy_add, int phy_reg) /* Only return ad bits of the gw register */ ret &= MLXBF_GIGE_MDIO_GW_AD_MASK; + /* The MDIO lock is set on read. To release it, clear gw register */ + writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); + return ret; } @@ -201,6 +204,9 @@ static int mlxbf_gige_mdio_write(struct mii_bus *bus, int phy_add, ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET, temp, !(temp & MLXBF_GIGE_MDIO_GW_BUSY_MASK), 100, 1000000); + /* The MDIO lock is set on read. To release it, clear gw register */ + writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET); + return ret; } -- 2.35.1