[PATCH 4.12 24/52] net/mlx5e: Fix DCB_CAP_ATTR_DCBX capability for DCBNL getcap.

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Huy Nguyen <huyn@xxxxxxxxxxxx>


[ Upstream commit 9e10bf1d349787f373484d835efe2dbb5f9c5614 ]

Current code doesn't report DCB_CAP_DCBX_HOST capability when query
through getcap. User space lldptool expects capability to have HOST mode
set when it wants to configure DCBX CEE mode. In absence of HOST mode
capability, lldptool fails to switch to CEE mode.

This fix returns DCB_CAP_DCBX_HOST capability when port's DCBX
controlled mode is under software control.

Fixes: 3a6a931dfb8e ("net/mlx5e: Support DCBX CEE API")
Signed-off-by: Huy Nguyen <huyn@xxxxxxxxxxxx>
Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/en.h       |    1 +
 drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c |   21 ++++++++++++---------
 2 files changed, 13 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -258,6 +258,7 @@ struct mlx5e_dcbx {
 
 	/* The only setting that cannot be read from FW */
 	u8                         tc_tsa[IEEE_8021QAZ_MAX_TCS];
+	u8                         cap;
 };
 #endif
 
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
@@ -288,13 +288,8 @@ static int mlx5e_dcbnl_ieee_setpfc(struc
 static u8 mlx5e_dcbnl_getdcbx(struct net_device *dev)
 {
 	struct mlx5e_priv *priv = netdev_priv(dev);
-	struct mlx5e_dcbx *dcbx = &priv->dcbx;
-	u8 mode = DCB_CAP_DCBX_VER_IEEE | DCB_CAP_DCBX_VER_CEE;
-
-	if (dcbx->mode == MLX5E_DCBX_PARAM_VER_OPER_HOST)
-		mode |= DCB_CAP_DCBX_HOST;
 
-	return mode;
+	return priv->dcbx.cap;
 }
 
 static u8 mlx5e_dcbnl_setdcbx(struct net_device *dev, u8 mode)
@@ -312,6 +307,7 @@ static u8 mlx5e_dcbnl_setdcbx(struct net
 		/* set dcbx to fw controlled */
 		if (!mlx5e_dcbnl_set_dcbx_mode(priv, MLX5E_DCBX_PARAM_VER_OPER_AUTO)) {
 			dcbx->mode = MLX5E_DCBX_PARAM_VER_OPER_AUTO;
+			dcbx->cap &= ~DCB_CAP_DCBX_HOST;
 			return 0;
 		}
 
@@ -324,6 +320,8 @@ static u8 mlx5e_dcbnl_setdcbx(struct net
 	if (mlx5e_dcbnl_switch_to_host_mode(netdev_priv(dev)))
 		return 1;
 
+	dcbx->cap = mode;
+
 	return 0;
 }
 
@@ -628,9 +626,9 @@ static u8 mlx5e_dcbnl_getcap(struct net_
 		*cap = false;
 		break;
 	case DCB_CAP_ATTR_DCBX:
-		*cap = (DCB_CAP_DCBX_LLD_MANAGED |
-			DCB_CAP_DCBX_VER_CEE |
-			DCB_CAP_DCBX_STATIC);
+		*cap = priv->dcbx.cap |
+		       DCB_CAP_DCBX_VER_CEE |
+		       DCB_CAP_DCBX_VER_IEEE;
 		break;
 	default:
 		*cap = 0;
@@ -760,5 +758,10 @@ void mlx5e_dcbnl_initialize(struct mlx5e
 	if (MLX5_CAP_GEN(priv->mdev, dcbx))
 		mlx5e_dcbnl_query_dcbx_mode(priv, &dcbx->mode);
 
+	priv->dcbx.cap = DCB_CAP_DCBX_VER_CEE |
+			 DCB_CAP_DCBX_VER_IEEE;
+	if (priv->dcbx.mode == MLX5E_DCBX_PARAM_VER_OPER_HOST)
+		priv->dcbx.cap |= DCB_CAP_DCBX_HOST;
+
 	mlx5e_ets_init(priv);
 }