[PATCH V2 net 3/8] net/mlx5e: Preserve tc-bw during parent changes

Mark Bloch
2025-08-20T13:33:07Z

From: Carolina Jubran <cjubran@nvidia.com>

When changing parent of a node/leaf with tc-bw configured, the code
saves and restores tc-bw values. However, it was reading the converted
hardware bw_share values (where 0 becomes 1) instead of the original
user values, causing incorrect tc-bw calculations after parent change.

Store original tc-bw values in the node structure and use them directly
for save/restore operations.

Fixes: cf7e73770d1b ("net/mlx5: Manage TC arbiter nodes and implement full support for tc-bw")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
.../net/ethernet/mellanox/mlx5/core/esw/qos.c | 24 +++++++++----------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index cd58d3934596..4ed5968f1638 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -102,6 +102,8 @@ struct mlx5_esw_sched_node {
u8 level;
/* Valid only when this node represents a traffic class. */
u8 tc;
+ /* Valid only for a TC arbiter node or vport TC arbiter. */
+ u32 tc_bw[DEVLINK_RATE_TCS_MAX];
};

static void esw_qos_node_attach_to_parent(struct mlx5_esw_sched_node *node)
@@ -609,10 +611,7 @@ static void
esw_qos_tc_arbiter_get_bw_shares(struct mlx5_esw_sched_node *tc_arbiter_node,
u32 *tc_bw)
{
- struct mlx5_esw_sched_node *vports_tc_node;
-
- list_for_each_entry(vports_tc_node, &tc_arbiter_node->children, entry)
- tc_bw[vports_tc_node->tc] = vports_tc_node->bw_share;
+ memcpy(tc_bw, tc_arbiter_node->tc_bw, sizeof(tc_arbiter_node->tc_bw));
}

static void
@@ -629,6 +628,7 @@ esw_qos_set_tc_arbiter_bw_shares(struct mlx5_esw_sched_node *tc_arbiter_node,
u8 tc = vports_tc_node->tc;
u32 bw_share;

+ tc_arbiter_node->tc_bw[tc] = tc_bw[tc];
bw_share = tc_bw[tc] * fw_max_bw_share;
bw_share = esw_qos_calc_bw_share(bw_share, divider,
fw_max_bw_share);
@@ -1060,6 +1060,7 @@ static void esw_qos_vport_disable(struct mlx5_vport *vport, struct netlink_ext_a
esw_qos_vport_tc_disable(vport, extack);

vport_node->bw_share = 0;
+ memset(vport_node->tc_bw, 0, sizeof(vport_node->tc_bw));
list_del_init(&vport_node->entry);
esw_qos_normalize_min_rate(vport_node->esw, vport_node->parent, extack);

@@ -1231,8 +1232,9 @@ static int esw_qos_vport_update(struct mlx5_vport *vport,
struct mlx5_esw_sched_node *parent,
struct netlink_ext_ack *extack)
{
- struct mlx5_esw_sched_node *curr_parent = vport->qos.sched_node->parent;
- enum sched_node_type curr_type = vport->qos.sched_node->type;
+ struct mlx5_esw_sched_node *vport_node = vport->qos.sched_node;
+ struct mlx5_esw_sched_node *curr_parent = vport_node->parent;
+ enum sched_node_type curr_type = vport_node->type;
u32 curr_tc_bw[DEVLINK_RATE_TCS_MAX] = {0};
int err;

@@ -1244,10 +1246,8 @@ static int esw_qos_vport_update(struct mlx5_vport *vport,
if (err)
return err;

- if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type) {
- esw_qos_tc_arbiter_get_bw_shares(vport->qos.sched_node,
- curr_tc_bw);
- }
+ if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type)
+ esw_qos_tc_arbiter_get_bw_shares(vport_node, curr_tc_bw);

esw_qos_vport_disable(vport, extack);

@@ -1258,8 +1258,8 @@ static int esw_qos_vport_update(struct mlx5_vport *vport,
}

if (curr_type == SCHED_NODE_TYPE_TC_ARBITER_TSAR && curr_type == type) {
- esw_qos_set_tc_arbiter_bw_shares(vport->qos.sched_node,
- curr_tc_bw, extack);
+ esw_qos_set_tc_arbiter_bw_shares(vport_node, curr_tc_bw,
+ extack);
}

return err;
--
2.34.1