Subject: Re: [PATCH net-next 10/13] net: phy: phy_link_topology: Add a helper to retrieve ports

From: kernel test robot <[email-masked]>
Date: Wed, 28 Jan 2026 06:23:19 +0800

Hi Maxime,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Maxime-Chevallier/net-phy-phy_port-Correctly-recompute-the-port-s-linkmodes/20260127-215318
base:   net-next/main
patch link:    https://lore.kernel.org/r/20260127134202.8208-11-maxime.chevallier%40bootlin.com
patch subject: [PATCH net-next 10/13] net: phy: phy_link_topology: Add a helper to retrieve ports
config: i386-randconfig-141-20260128 (https://download.01.org/0day-ci/archive/20260128/[email-masked]/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
smatch version: v0.5.0-8994-gd50c5a4c
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260128/[email-masked]/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 <[email-masked]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email-masked]/

All errors (new ones prefixed by >>):

   In file included from net/core/dev.c:165:
>> include/linux/phy_link_topology.h:110:1: error: return type defaults to 'int' [-Wimplicit-int]
     110 | phy_link_topo_get_port(struct net_device *dev, u32 port_id)
         | ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/phy_link_topology.h:110:1: warning: no previous prototype for 'phy_link_topo_get_port' [-Wmissing-prototypes]
   In file included from include/uapi/linux/posix_types.h:5,
                    from include/uapi/linux/types.h:14,
                    from include/linux/types.h:6,
                    from include/linux/kasan-checks.h:5,
                    from include/asm-generic/rwonce.h:26,
                    from ./arch/x86/include/generated/asm/rwonce.h:1,
                    from include/linux/compiler.h:380,
                    from include/linux/cleanup.h:5,
                    from include/linux/uaccess.h:5,
                    from net/core/dev.c:71:
   include/linux/phy_link_topology.h: In function 'phy_link_topo_get_port':
>> include/linux/stddef.h:8:14: error: returning 'void *' from a function with return type 'int' makes integer from pointer without a cast [-Wint-conversion]
       8 | #define NULL ((void *)0)
         |              ^
   include/linux/phy_link_topology.h:112:16: note: in expansion of macro 'NULL'
     112 |         return NULL;
         |                ^~~~

vim +/int +110 include/linux/phy_link_topology.h

   109	
 > 110	phy_link_topo_get_port(struct net_device *dev, u32 port_id)
   111	{
   112		return NULL;
   113	}
   114	#endif
   115	

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