From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Shay Drory <shayd@nvidia.com>,
	Moshe Shemesh <moshe@nvidia.com>,
	Tariq Toukan <tariqt@nvidia.com>,
	Jacob Keller <Jacob.e.keller@intel.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.18 559/641] net/mlx5: Fix multiport device check over light SFs
Date: Tue, 24 Feb 2026 17:24:45 -0800
Message-ID: <20260225012402.068511546@linuxfoundation.org>
In-Reply-To: <20260225012348.915798704@linuxfoundation.org>
References: <20260225012348.915798704@linuxfoundation.org>
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6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shay Drory <shayd@nvidia.com>

[ Upstream commit 47bf2e813817159f4d195be83a9b5a640ee6baec ]

Driver is using num_vhca_ports capability to distinguish between
multiport master device and multiport slave device. num_vhca_ports is a
capability the driver sets according to the MAX num_vhca_ports
capability reported by FW. On the other hand, light SFs doesn't set the
above capbility.

This leads to wrong results whenever light SFs is checking whether he is
a multiport master or slave.

Therefore, use the MAX capability to distinguish between master and
slave devices.

Fixes: e71383fb9cd1 ("net/mlx5: Light probe local SFs")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Jacob Keller <Jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260218072904.1764634-2-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/linux/mlx5/driver.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 5405ca1038f9e..85c2b3d358ec1 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -1274,12 +1274,12 @@ static inline bool mlx5_rl_is_supported(struct mlx5_core_dev *dev)
 static inline int mlx5_core_is_mp_slave(struct mlx5_core_dev *dev)
 {
 	return MLX5_CAP_GEN(dev, affiliate_nic_vport_criteria) &&
-	       MLX5_CAP_GEN(dev, num_vhca_ports) <= 1;
+	       MLX5_CAP_GEN_MAX(dev, num_vhca_ports) <= 1;
 }
 
 static inline int mlx5_core_is_mp_master(struct mlx5_core_dev *dev)
 {
-	return MLX5_CAP_GEN(dev, num_vhca_ports) > 1;
+	return MLX5_CAP_GEN_MAX(dev, num_vhca_ports) > 1;
 }
 
 static inline int mlx5_core_mp_enabled(struct mlx5_core_dev *dev)
-- 
2.51.0