linux-kernel - Re: [PATCH net-next 3/4] net: phy: realtek: use paged access for MDIO_MMD

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Message-ID: <202601050128.DGivvUie-lkp@intel.com>
Date: Mon, 5 Jan 2026 01:52:33 +0100
From: kernel test robot <lkp@...el.com>
To: Daniel Golle <daniel@...rotopia.org>, Andrew Lunn <andrew@...n.ch>,
	Heiner Kallweit <hkallweit1@...il.com>,
	Russell King <linux@...linux.org.uk>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Vladimir Oltean <vladimir.oltean@....com>,
	Michael Klein <michael@...sekall.de>,
	Aleksander Jan Bajkowski <olek2@...pl>,
	Bevan Weiss <bevan.weiss@...il.com>, linux-kernel@...r.kernel.org
Cc: oe-kbuild-all@...ts.linux.dev, netdev@...r.kernel.org
Subject: Re: [PATCH net-next 3/4] net: phy: realtek: use paged access for
 MDIO_MMD_VEND2 in C22 mode

Hi Daniel,

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/Daniel-Golle/net-phy-realtek-fix-whitespace-in-struct-phy_driver-initializers/20260104-211500
base:   net-next/main
patch link:    https://lore.kernel.org/r/d7053fe51fb857b634880be5dcec253858f01aff.1767531485.git.daniel%40makrotopia.org
patch subject: [PATCH net-next 3/4] net: phy: realtek: use paged access for MDIO_MMD_VEND2 in C22 mode
config: x86_64-rhel-9.4-ltp (https://download.01.org/0day-ci/archive/20260105/202601050128.DGivvUie-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260105/202601050128.DGivvUie-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@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601050128.DGivvUie-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/net/phy/realtek/realtek_main.c: In function 'rtl822xb_read_mmd':
>> drivers/net/phy/realtek/realtek_main.c:1261:51: error: 'mmdreg' undeclared (first use in this function); did you mean 'mmdrop'?
    1261 |                                           devnum, mmdreg);
         |                                                   ^~~~~~
         |                                                   mmdrop
   drivers/net/phy/realtek/realtek_main.c:1261:51: note: each undeclared identifier is reported only once for each function it appears in
   drivers/net/phy/realtek/realtek_main.c: In function 'rtl822xb_write_mmd':
   drivers/net/phy/realtek/realtek_main.c:1309:52: error: 'mmdreg' undeclared (first use in this function); did you mean 'mmdrop'?
    1309 |                                            devnum, mmdreg, val);
         |                                                    ^~~~~~
         |                                                    mmdrop


vim +1261 drivers/net/phy/realtek/realtek_main.c

  1248	
  1249	/* RTL822x cannot access MDIO_MMD_VEND2 via MII_MMD_CTRL/MII_MMD_DATA.
  1250	 * A mapping to use paged access needs to be used instead.
  1251	 * All other MMD devices can be accessed as usual.
  1252	 */
  1253	static int rtl822xb_read_mmd(struct phy_device *phydev, int devnum, u16 reg)
  1254	{
  1255		int oldpage, ret, read_ret;
  1256		u16 page;
  1257	
  1258		/* Use Clause-45 bus access in case it is available */
  1259		if (phydev->is_c45)
  1260			return __mdiobus_c45_read(phydev->mdio.bus, phydev->mdio.addr,
> 1261						  devnum, mmdreg);
  1262	
  1263		/* Use indirect access via MII_MMD_CTRL and MII_MMD_DATA for all
  1264		 * MMDs except MDIO_MMD_VEND2
  1265		 */
  1266		if (devnum != MDIO_MMD_VEND2) {
  1267			__mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
  1268					MII_MMD_CTRL, devnum);
  1269			__mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
  1270					MII_MMD_DATA, mmdreg);
  1271			__mdiobus_write(phydev->mdio.bus, phydev->mdio.addr,
  1272					MII_MMD_CTRL, devnum | MII_MMD_CTRL_NOINCR);
  1273	
  1274			return __mdiobus_read(phydev->mdio.bus, phydev->mdio.addr,
  1275					       MII_MMD_DATA);
  1276		}
  1277	
  1278		/* Use paged access for MDIO_MMD_VEND2 over Clause-22 */
  1279		page = RTL822X_VND2_TO_PAGE(reg);
  1280		oldpage = __phy_read(phydev, RTL821x_PAGE_SELECT);
  1281		if (oldpage < 0)
  1282			return ret;
  1283	
  1284		if (oldpage != page) {
  1285			ret = __phy_write(phydev, RTL821x_PAGE_SELECT, page);
  1286			if (ret < 0)
  1287				return ret;
  1288		}
  1289	
  1290		read_ret = __phy_read(phydev, RTL822X_VND2_TO_PAGE_REG(reg));
  1291		if (oldpage != page) {
  1292			ret = __phy_write(phydev, RTL821x_PAGE_SELECT, oldpage);
  1293			if (ret < 0)
  1294				return ret;
  1295		}
  1296	
  1297		return read_ret;
  1298	}
  1299	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki