net/mlx5e: Mutually exclude setting of TX-port-TS and MQPRIO in channel mode

TX-port-TS hijacks the PTP traffic to a specific HW TX-queue. This
conflicts with MQPRIO in channel mode, which specifies explicitly which
TC accepts the packet. This patch mutually excludes the above
configuration.

Fixes: ec60c458 ("net/mlx5e: Support MQPRIO channel mode")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c

@@ -2036,6 +2036,17 @@ static int set_pflag_tx_port_ts(struct net_device *netdev, bool enable)
 	}
 
 	new_params = priv->channels.params;
+	/* Don't allow enabling TX-port-TS if MQPRIO mode channel  offload is
+	 * active, since it defines explicitly which TC accepts the packet.
+	 * This conflicts with TX-port-TS hijacking the PTP traffic to a specific
+	 * HW TX-queue.
+	 */
+	if (enable && new_params.mqprio.mode == TC_MQPRIO_MODE_CHANNEL) {
+		netdev_err(priv->netdev,
+			   "%s: MQPRIO mode channel offload is active, cannot set the TX-port-TS\n",
+			   __func__);
+		return -EINVAL;
+	}
 	MLX5E_SET_PFLAG(&new_params, MLX5E_PFLAG_TX_PORT_TS, enable);
 	/* No need to verify SQ stop room as
 	 * ptpsq.txqsq.stop_room <= generic_sq->stop_room, and both

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -2945,9 +2945,17 @@ static int mlx5e_mqprio_channel_validate(struct mlx5e_priv *priv,
 					 struct tc_mqprio_qopt_offload *mqprio)
 {
 	struct net_device *netdev = priv->netdev;
+	struct mlx5e_ptp *ptp_channel;
 	int agg_count = 0;
 	int i;
 
+	ptp_channel = priv->channels.ptp;
+	if (ptp_channel && test_bit(MLX5E_PTP_STATE_TX, ptp_channel->state)) {
+		netdev_err(netdev,
+			   "Cannot activate MQPRIO mode channel since it conflicts with TX port TS\n");
+		return -EINVAL;
+	}
+
 	if (mqprio->qopt.offset[0] != 0 || mqprio->qopt.num_tc < 1 ||
 	    mqprio->qopt.num_tc > MLX5E_MAX_NUM_MQPRIO_CH_TC)
 		return -EINVAL;