Hi Oleksij,

I love your patch! Perhaps something to improve:

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

url:    https://github.com/0day-ci/linux/commits/Oleksij-Rempel/ar9331-mainline-some-parts-of-switch-functionality/20210403-195131
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 82506665179209e43d3c9d39ffa42f8c8ff968bd
config: powerpc-randconfig-r035-20210403 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 0fe8af94688aa03c01913c2001d6a1a911f42ce6)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # https://github.com/0day-ci/linux/commit/1d06a86ebc7af4decbdf92e3114a6d983063eca1
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Oleksij-Rempel/ar9331-mainline-some-parts-of-switch-functionality/20210403-195131
        git checkout 1d06a86ebc7af4decbdf92e3114a6d983063eca1
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:619:
   arch/powerpc/include/asm/io-defs.h:43:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insb, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:97:1: note: expanded from here
   __do_insb
   ^
   arch/powerpc/include/asm/io.h:556:56: note: expanded from macro '__do_insb'
   #define __do_insb(p, b, n)      readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/net/dsa/qca/ar9331.c:44:
   In file included from include/linux/of_irq.h:7:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:619:
   arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:99:1: note: expanded from here
   __do_insw
   ^
   arch/powerpc/include/asm/io.h:557:56: note: expanded from macro '__do_insw'
   #define __do_insw(p, b, n)      readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/net/dsa/qca/ar9331.c:44:
   In file included from include/linux/of_irq.h:7:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:619:
   arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:101:1: note: expanded from here
   __do_insl
   ^
   arch/powerpc/include/asm/io.h:558:56: note: expanded from macro '__do_insl'
   #define __do_insl(p, b, n)      readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n))
                                          ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/net/dsa/qca/ar9331.c:44:
   In file included from include/linux/of_irq.h:7:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:619:
   arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:103:1: note: expanded from here
   __do_outsb
   ^
   arch/powerpc/include/asm/io.h:559:58: note: expanded from macro '__do_outsb'
   #define __do_outsb(p, b, n)     writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/net/dsa/qca/ar9331.c:44:
   In file included from include/linux/of_irq.h:7:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:619:
   arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:105:1: note: expanded from here
   __do_outsw
   ^
   arch/powerpc/include/asm/io.h:560:58: note: expanded from macro '__do_outsw'
   #define __do_outsw(p, b, n)     writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from drivers/net/dsa/qca/ar9331.c:44:
   In file included from include/linux/of_irq.h:7:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:619:
   arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:107:1: note: expanded from here
   __do_outsl
   ^
   arch/powerpc/include/asm/io.h:561:58: note: expanded from macro '__do_outsl'
   #define __do_outsl(p, b, n)     writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
>> drivers/net/dsa/qca/ar9331.c:971:47: warning: variable 'f2' is uninitialized when used here [-Wuninitialized]
           ret = ar9331_sw_port_fdb_write(priv, f0, f1, f2);
                                                        ^~
   drivers/net/dsa/qca/ar9331.c:961:16: note: initialize the variable 'f2' to silence this warning
           u32 f0, f1, f2;
                         ^
                          = 0
   7 warnings generated.


vim +/f2 +971 drivers/net/dsa/qca/ar9331.c

   954	
   955	static int ar9331_sw_port_fdb_rmw(struct ar9331_sw_priv *priv,
   956					  const unsigned char *mac,
   957					  u8 port_mask_set,
   958					  u8 port_mask_clr)
   959	{
   960		struct regmap *regmap = priv->regmap;
   961		u32 f0, f1, f2;
   962		u8 port_mask, port_mask_new, status, func;
   963		int ret;
   964	
   965		ret = ar9331_sw_fdb_wait(priv, &f0);
   966		if (ret)
   967			return ret;
   968	
   969		ar9331_sw_port_fdb_prepare(mac, &f0, &f1, AR9331_SW_AT_FUNC_FIND_MAC);
   970	
 > 971		ret = ar9331_sw_port_fdb_write(priv, f0, f1, f2);
   972		if (ret)
   973			return ret;
   974	
   975		ret = ar9331_sw_fdb_wait(priv, &f0);
   976		if (ret)
   977			return ret;
   978	
   979		ret = regmap_read(regmap, AR9331_SW_REG_ADDR_TABLE_FUNCTION2, &f2);
   980		if (ret)
   981			return ret;
   982	
   983		port_mask = FIELD_GET(AR9331_SW_AT_DES_PORT, f2);
   984		status = FIELD_GET(AR9331_SW_AT_STATUS, f2);
   985		if (status > 0 && status < AR9331_SW_AT_STATUS_STATIC) {
   986			dev_err_ratelimited(priv->dev, "%s: found existing dynamic entry on %x\n",
   987					    __func__, port_mask);
   988	
   989			if (port_mask_set && port_mask_set != port_mask)
   990				dev_err_ratelimited(priv->dev, "%s: found existing dynamic entry on %x, replacing it with static on %x\n",
   991						    __func__, port_mask, port_mask_set);
   992			port_mask = 0;
   993		} else if (!status && !port_mask_set) {
   994			return 0;
   995		}
   996	
   997		port_mask_new = port_mask & ~port_mask_clr;
   998		port_mask_new |= port_mask_set;
   999	
  1000		if (port_mask_new == port_mask &&
  1001		    status == AR9331_SW_AT_STATUS_STATIC) {
  1002			dev_info(priv->dev, "%s: no need to overwrite existing valid entry on %x\n",
  1003					    __func__, port_mask_new);
  1004			return 0;
  1005		}
  1006	
  1007		if (port_mask_new) {
  1008			func = AR9331_SW_AT_FUNC_LOAD_ENTRY;
  1009		} else {
  1010			func = AR9331_SW_AT_FUNC_PURGE_ENTRY;
  1011			port_mask_new = port_mask;
  1012		}
  1013	
  1014		f2 = FIELD_PREP(AR9331_SW_AT_DES_PORT, port_mask_new) |
  1015			FIELD_PREP(AR9331_SW_AT_STATUS, AR9331_SW_AT_STATUS_STATIC);
  1016	
  1017		ar9331_sw_port_fdb_prepare(mac, &f0, &f1, func);
  1018	
  1019		ret = ar9331_sw_port_fdb_write(priv, f0, f1, f2);
  1020		if (ret)
  1021			return ret;
  1022	
  1023		ret = ar9331_sw_fdb_wait(priv, &f0);
  1024		if (ret)
  1025			return ret;
  1026	
  1027		if (f0 & AR9331_SW_AT_FULL_VIO) {
  1028			/* cleanup error status */
  1029			regmap_write(regmap, AR9331_SW_REG_ADDR_TABLE_FUNCTION0, 0);
  1030			dev_err_ratelimited(priv->dev, "%s: can't add new entry, ATU is full\n", __func__);
  1031			return -ENOMEM;
  1032		}
  1033	
  1034		return 0;
  1035	}
  1036	

---
0-DAY CI Kernel Test Service, Intel Corporation
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