diff options
| author | Bobby Eshleman <bobbyeshleman@meta.com> | 2026-08-03 16:47:29 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-04 19:00:36 -0700 |
| commit | e7386770be1bf810bcd6af39d1e4bfeab3408430 (patch) | |
| tree | 6a4192f88831cad2baf49ccc3361204d1a57df11 /drivers | |
| parent | 5d1c224dd914579524a183a514c12b95095d12ce (diff) | |
net/mlx5e: fix BQL reset on SQ re-activation
mlx5e_queue_start() deactivates and re-activates all channels but closes
only the queue being restarted. mlx5e_activate_txqsq() then
unconditionally calls netdev_tx_reset_queue(), zeroing the BQL counters
of channels that kept their in-flight TX WQEs. The next completion then
over-charges and trips the BUG_ON() in dql_completed():
kernel BUG at lib/dynamic_queue_limits.c:99!
RIP: 0010:dql_completed+0x23d/0x280
Call Trace:
<IRQ>
mlx5e_poll_tx_cq+0x668/0xa60
mlx5e_napi_poll+0x5b/0x7b0
net_rx_action+0x15a/0x580
Reset BQL only when the SQ has no bytes in flight (sq->cc == sq->pc).
In the case that reset is skipped, the outstanding WQEs will eventually
complete and rebalance the dql. The dql->limit is carried across the
reset.
Fixes: b2588ea40ec9 ("net/mlx5e: Implement queue mgmt ops and single channel swap")
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260803-mlx5-bql-v3-1-a30d4c66fe1d@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 7d47a1da8b6b..f0407a850ea8 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -1939,8 +1939,10 @@ err_free_txqsq: void mlx5e_activate_txqsq(struct mlx5e_txqsq *sq) { sq->txq = netdev_get_tx_queue(sq->netdev, sq->txq_ix); + /* Reset BQL only when the SQ has no bytes in flight. */ + if (sq->cc == sq->pc) + netdev_tx_reset_queue(sq->txq); set_bit(MLX5E_SQ_STATE_ENABLED, &sq->state); - netdev_tx_reset_queue(sq->txq); netif_tx_start_queue(sq->txq); netif_queue_set_napi(sq->netdev, sq->txq_ix, NETDEV_QUEUE_TYPE_TX, sq->cq.napi); } |