Re: [PATCH net 09/11] net/mlx5e: Update and set Xon/Xoff upon MTU set

[Mark Bloch <mbloch@nvidia.com>]

On 24/08/2025 16:54, kernel test robot wrote:
> Hi Mark,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on ec79003c5f9d2c7f9576fc69b8dbda80305cbe3a]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Mark-Bloch/net-mlx5-HWS-Fix-memory-leak-in-hws_pool_buddy_init-error-path/20250824-164938
> base:   ec79003c5f9d2c7f9576fc69b8dbda80305cbe3a
> patch link:    https://lore.kernel.org/r/20250824083944.523858-10-mbloch%40nvidia.com
> patch subject: [PATCH net 09/11] net/mlx5e: Update and set Xon/Xoff upon MTU set
> config: um-randconfig-002-20250824 (https://download.01.org/0day-ci/archive/20250824/202508242120.QljNCAgz-lkp@intel.com/config)
> compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project d26ea02060b1c9db751d188b2edb0059a9eb273d)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250824/202508242120.QljNCAgz-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202508242120.QljNCAgz-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from drivers/net/ethernet/mellanox/mlx5/core/en_main.c:34:
>    In file included from include/net/tc_act/tc_gact.h:5:
>    In file included from include/net/act_api.h:10:
>    In file included from include/net/flow_offload.h:6:
>    In file included from include/linux/netlink.h:7:
>    In file included from include/linux/skbuff.h:17:
>    In file included from include/linux/bvec.h:10:
>    In file included from include/linux/highmem.h:12:
>    In file included from include/linux/hardirq.h:11:
>    In file included from arch/um/include/asm/hardirq.h:5:
>    In file included from include/asm-generic/hardirq.h:17:
>    In file included from include/linux/irq.h:20:
>    In file included from include/linux/io.h:12:
>    In file included from arch/um/include/asm/io.h:24:
>    include/asm-generic/io.h:1175:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
>     1175 |         return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
>          |                                                   ~~~~~~~~~~ ^
>    In file included from drivers/net/ethernet/mellanox/mlx5/core/en_main.c:52:
>>> drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.h:79:12: warning: declaration of 'struct ieee_pfc' will not be visible outside of this function [-Wvisibility]
>       79 |                                 struct ieee_pfc *pfc,
>          |                                        ^
>    2 warnings generated.

It seems net/dcbnl.h is only included (via linux/netdevice.h)
if CONFIG_DCB is set. We've tested only by not setting
CONFIG_MLX5_CORE_EN_DCB but left CONFIG_DCB set so it was missed.
Will fix.

Mark

> 
> 
> vim +79 drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.h
> 
>     68	
>     69	#ifdef CONFIG_MLX5_CORE_EN_DCB
>     70	int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
>     71					    u32 change, unsigned int mtu,
>     72					    struct ieee_pfc *pfc,
>     73					    u32 *buffer_size,
>     74					    u8 *prio2buffer);
>     75	#else
>     76	static inline int
>     77	mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
>     78					u32 change, unsigned int mtu,
>   > 79					struct ieee_pfc *pfc,
>     80					u32 *buffer_size,
>     81					u8 *prio2buffer)
>     82	{
>     83		return 0;
>     84	}
>     85	#endif
>     86	
>