> struct ax88172a_private { > struct mii_bus *mdio; > struct phy_device *phydev; > - char phy_name[20]; > + char phy_name[MII_BUS_ID_SIZE + 5]; Could you explain the + 5? https://elixir.bootlin.com/linux/v6.13.7/source/drivers/net/ethernet/davicom/dm9051.c#L1156 https://elixir.bootlin.com/linux/v6.13.7/source/drivers/net/ethernet/freescale/fec_main.c#L2454 https://elixir.bootlin.com/linux/v6.13.7/source/drivers/net/ethernet/xilinx/ll_temac.h#L348 The consensus seems to be + 3. Andrew