From: Huy Nguyen <huyn@mellanox.com>

Date: Fri, 6 Sep 2019 09:28:46 -0500

Subject: net/mlx5e: Query global pause state before setting prio2buffer

Patch-mainline: v5.5-rc1

Git-commit: 73e6551699a32fac703ceea09214d6580edcf2d5

References: bsc#1103990 FATE#326006

When the user changes prio2buffer mapping while global pause is

enabled, mlx5 driver incorrectly sets all active buffers

(buffer that has at least one priority mapped) to lossy.

Solution:

If global pause is enabled, set all the active buffers to lossless

in prio2buffer command.

Also, add error message when buffer size is not enough to meet

xoff threshold.

Fixes: 0696d60853d5 ("net/mlx5e: Receive buffer configuration")

Signed-off-by: Huy Nguyen <huyn@mellanox.com>

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>

---

 drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c |   27 +++++++++++++--

 1 file changed, 25 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c

+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c

@@ -155,8 +155,11 @@ static int update_xoff_threshold(struct

 		}

 		if (port_buffer->buffer[i].size <

-		    (xoff + max_mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))

+		    (xoff + max_mtu + (1 << MLX5E_BUFFER_CELL_SHIFT))) {

+			pr_err("buffer_size[%d]=%d is not enough for lossless buffer\n",

+			       i, port_buffer->buffer[i].size);

 			return -ENOMEM;

+		}

 		port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;

 		port_buffer->buffer[i].xon  =

@@ -232,6 +235,26 @@ static int update_buffer_lossy(unsigned

 	return 0;

 }

+static int fill_pfc_en(struct mlx5_core_dev *mdev, u8 *pfc_en)

+{

+	u32 g_rx_pause, g_tx_pause;

+	int err;

+

+	err = mlx5_query_port_pause(mdev, &g_rx_pause, &g_tx_pause);

+	if (err)

+		return err;

+

+	/* If global pause enabled, set all active buffers to lossless.

+	 * Otherwise, check PFC setting.

+	 */

+	if (g_rx_pause || g_tx_pause)

+		*pfc_en = 0xff;

+	else

+		err = mlx5_query_port_pfc(mdev, pfc_en, NULL);

+

+	return err;

+}

+

 #define MINIMUM_MAX_MTU 9216

 int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,

 				    u32 change, unsigned int mtu,

@@ -277,7 +300,7 @@ int mlx5e_port_manual_buffer_config(stru

 	if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {

 		update_prio2buffer = true;

-		err = mlx5_query_port_pfc(priv->mdev, &curr_pfc_en, NULL);

+		err = fill_pfc_en(priv->mdev, &curr_pfc_en);

 		if (err)

 			return err;