net/mlx5e: Report zero bandwidth for non-ETS traffic classes

[ Upstream commit ffb1873 ]

The IEEE 802.1Qaz standard defines that bandwidth allocation percentages
only apply to Enhanced Transmission Selection (ETS) traffic classes.
For STRICT and VENDOR transmission selection algorithms, bandwidth
percentage values are not applicable.

Currently for non-ETS 100 bandwidth is being reported for all traffic
classes in the get operation due to hardware limitation, regardless of
their TSA type.

Fix this by reporting 0 for non-ETS traffic classes.

Fixes: 820c2c5 ("net/mlx5e: Read ETS settings directly from firmware")
Signed-off-by: Alexei Lazar <alazar@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Link: https://patch.msgid.link/20260717075125.1244877-2-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Alexei Lazar

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

@@ -158,6 +158,13 @@ static int mlx5e_dcbnl_ieee_getets(struct net_device *netdev,
 	}
 	memcpy(ets->tc_tsa, priv->dcbx.tc_tsa, sizeof(ets->tc_tsa));
 
+	/* Report 0 for non ETS TSA */
+	for (i = 0; i < ets->ets_cap; i++) {
+		if (ets->tc_tx_bw[i] == MLX5E_MAX_BW_ALLOC &&
+		    priv->dcbx.tc_tsa[i] != IEEE_8021QAZ_TSA_ETS)
+			ets->tc_tx_bw[i] = 0;
+	}
+
 	return err;
 }