[PATCH net-next 6/9] net/mlx4_en: Adding support of turning off link autonegotiation via ethtool

[Tariq Toukan]

From: Ariel Levkovich <lar...@mellanox.com>

This feature will allow the user to disable auto negotiation
on the port for mlx4 devices while setting the speed is limited
to 1GbE speeds.
Other speeds will not be accepted in autoneg off mode.

Signed-off-by: Ariel Levkovich <lar...@mellanox.com>
Signed-off-by: Tariq Toukan <tar...@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_ethtool.c | 24 +++++++++++++++++++-----
 include/linux/mlx4/device.h                     |  7 ++++++-
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c 
b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index 0ab644b6c2e6..5d11433fcc37 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -902,6 +902,7 @@ static __be32 speed_set_ptys_admin(struct mlx4_en_priv 
*priv, u32 speed,
        struct mlx4_en_priv *priv = netdev_priv(dev);
        struct mlx4_ptys_reg ptys_reg;
        __be32 proto_admin;
+       u8 cur_autoneg;
        int ret;
 
        u32 ptys_adv = ethtool2ptys_link_modes(
@@ -931,10 +932,21 @@ static __be32 speed_set_ptys_admin(struct mlx4_en_priv 
*priv, u32 speed,
                return 0;
        }
 
-       proto_admin = link_ksettings->base.autoneg == AUTONEG_ENABLE ?
-               cpu_to_be32(ptys_adv) :
-               speed_set_ptys_admin(priv, speed,
-                                    ptys_reg.eth_proto_cap);
+       cur_autoneg = ptys_reg.flags & MLX4_PTYS_AN_DISABLE_ADMIN ?
+                               AUTONEG_DISABLE : AUTONEG_ENABLE;
+
+       if (link_ksettings->base.autoneg == AUTONEG_DISABLE) {
+               proto_admin = speed_set_ptys_admin(priv, speed,
+                                                  ptys_reg.eth_proto_cap);
+               if ((be32_to_cpu(proto_admin) &
+                    (MLX4_PROT_MASK(MLX4_1000BASE_CX_SGMII) |
+                     MLX4_PROT_MASK(MLX4_1000BASE_KX))) &&
+                   (ptys_reg.flags & MLX4_PTYS_AN_DISABLE_CAP))
+                       ptys_reg.flags |= MLX4_PTYS_AN_DISABLE_ADMIN;
+       } else {
+               proto_admin = cpu_to_be32(ptys_adv);
+               ptys_reg.flags &= ~MLX4_PTYS_AN_DISABLE_ADMIN;
+       }
 
        proto_admin &= ptys_reg.eth_proto_cap;
        if (!proto_admin) {
@@ -942,7 +954,9 @@ static __be32 speed_set_ptys_admin(struct mlx4_en_priv 
*priv, u32 speed,
                return -EINVAL; /* nothing to change due to bad input */
        }
 
-       if (proto_admin == ptys_reg.eth_proto_admin)
+       if ((proto_admin == ptys_reg.eth_proto_admin) &&
+           ((ptys_reg.flags & MLX4_PTYS_AN_DISABLE_CAP) &&
+            (link_ksettings->base.autoneg == cur_autoneg)))
                return 0; /* Nothing to change */
 
        en_dbg(DRV, priv, "mlx4_ACCESS_PTYS_REG SET: ptys_reg.eth_proto_admin = 
0x%x\n",
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index 6533c16e27ad..c3ac945b2759 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -1539,8 +1539,13 @@ enum mlx4_ptys_proto {
        MLX4_PTYS_EN = 1<<2,
 };
 
+enum mlx4_ptys_flags {
+       MLX4_PTYS_AN_DISABLE_CAP   = 1 << 5,
+       MLX4_PTYS_AN_DISABLE_ADMIN = 1 << 6,
+};
+
 struct mlx4_ptys_reg {
-       u8 resrvd1;
+       u8 flags;
        u8 local_port;
        u8 resrvd2;
        u8 proto_mask;
-- 
1.8.3.1