[PATCH net] net/mlx5e: Fix ETS zero BW reporting when one TC holds 100%

[PATCH net] net/mlx5e: Fix ETS zero BW reporting when one TC holds 100%

[Tariq Toukan]

From: Carolina Jubran <cjubran@nvidia.com>

When ETS TCs with zero bandwidth are configured, the driver programs the
firmware using an alternate representation. On get, it needs
to recognize that representation so those TCs can be translated back and
reported as 0% bandwidth.

The existing detection relied on the programmed bandwidth because it was
enough to identify this representation. However, when a single ETS TC
owns 100% of the bandwidth, its firmware representation becomes the
same as a strict-priority TC, causing zero-bandwidth ETS TCs to be
reported with non-zero bandwidth values.

Use the cached TSA instead to distinguish the ETS and strict-priority
cases.

Fixes: be0f161ef141 ("net/mlx5e: DCBNL, Implement tc with ets type and zero bandwidth")
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Alex Lazar <alazar@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
index 00e706e1ede1..741f75b5bfec 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
@@ -148,7 +148,7 @@ static int mlx5e_dcbnl_ieee_getets(struct net_device *netdev,
 		if (err)
 			return err;
 
-		if (ets->tc_tx_bw[i] < MLX5E_MAX_BW_ALLOC &&
+		if (priv->dcbx.tc_tsa[i] == IEEE_8021QAZ_TSA_ETS &&
 		    tc_group[i] == (MLX5E_LOWEST_PRIO_GROUP + 1))
 			is_zero_bw_ets_tc = true;
 
-- 
2.44.0

Re: [PATCH net] net/mlx5e: Fix ETS zero BW reporting when one TC holds 100%

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Wed, 2 Sep 2026 22:32:24 +0300 you wrote:
> From: Carolina Jubran <cjubran@nvidia.com>
> 
> When ETS TCs with zero bandwidth are configured, the driver programs the
> firmware using an alternate representation. On get, it needs
> to recognize that representation so those TCs can be translated back and
> reported as 0% bandwidth.
> 
> [...]

Here is the summary with links:
  - [net] net/mlx5e: Fix ETS zero BW reporting when one TC holds 100%
    https://git.kernel.org/netdev/net/c/e7ee89740800

You are awesome, thank you!
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