Re: [PATCH net-next v15 5/5] net: dsa: motorcomm: Add support for Motorcomm YT922x

From: kernel test robot

Date: Mon Oct 19 2026 - 22:18:09 EST


Hi Kyle,

kernel test robot noticed the following build warnings:

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

url: https://github.com/intel-lab-lkp/linux/commits/Kyle-Switch/net-dsa-motorcomm-initialize-dsa_switch-based-on-chipid/20261019-190539
base: net-next/main
patch link: https://lore.kernel.org/r/20261019110543.2999419-6-kyle.switch%40motor-comm.com
patch subject: [PATCH net-next v15 5/5] net: dsa: motorcomm: Add support for Motorcomm YT922x
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20261020/202610200942.aPmEAZ8C-lkp@xxxxxxxxx/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 6719b9e31d6a93099612c474eec76d9f41d0275a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261020/202610200942.aPmEAZ8C-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202610200942.aPmEAZ8C-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> drivers/net/dsa/motorcomm/chip.c:2755:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
2755 | default:
| ^
drivers/net/dsa/motorcomm/chip.c:2755:2: note: insert '__attribute__((fallthrough));' to silence this warning
2755 | default:
| ^
| __attribute__((fallthrough));
drivers/net/dsa/motorcomm/chip.c:2755:2: note: insert 'break;' to avoid fall-through
2755 | default:
| ^
| break;
1 warning generated.


vim +2755 drivers/net/dsa/motorcomm/chip.c

2730
2731 static int
2732 yt922x_port_config(struct yt921x_priv *priv, int port, unsigned int mode,
2733 phy_interface_t interface)
2734 {
2735 struct device *dev = yt921x_priv_to_device(priv);
2736 const struct yt921x_info *info = priv->info;
2737 struct yt921x_port *pp = &priv->ports[port];
2738
2739 if (BIT(port) & info->internal_mask) {
2740 if (interface != PHY_INTERFACE_MODE_INTERNAL)
2741 goto err;
2742 return 0;
2743 }
2744
2745 switch (interface) {
2746 /* SERDES */
2747 case PHY_INTERFACE_MODE_SGMII:
2748 case PHY_INTERFACE_MODE_100BASEX:
2749 case PHY_INTERFACE_MODE_1000BASEX:
2750 case PHY_INTERFACE_MODE_2500BASEX:
2751 case PHY_INTERFACE_MODE_USXGMII:
2752 if (!(BIT(port) & info->serdes_mask))
2753 goto err;
2754 pp->serdes = true;
> 2755 default:
2756 goto err;
2757 }
2758
2759 return 0;
2760
2761 err:
2762 dev_err(dev, "Wrong mode %d on port %d\n", interface, port);
2763 return -EINVAL;
2764 }
2765

--
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https://github.com/intel/lkp-tests/wiki