[arm-platforms:kvm-arm64/mmu-pgt 773/874] arch/arc/include/uapi/asm/swab.h:28:9: warning: 'txchain' is used uninitialized

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm-arm64/mmu-pgt
head:   1ed29f79e7c6441ef29c25a43d7c82d91e884dcc
commit: e529bcaa17060f516d1e4f345ea460ea206317d1 [773/874] [brcmfmac] Compute number of available antennas and set it in wiphy structure.
config: arc-allmodconfig (https://download.01.org/0day-ci/archive/20240519/202405190213.5s1Al3aa-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240519/202405190213.5s1Al3aa-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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202405190213.5s1Al3aa-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/uapi/linux/swab.h:8,
                    from include/linux/swab.h:5,
                    from include/uapi/linux/byteorder/big_endian.h:14,
                    from include/linux/byteorder/big_endian.h:5,
                    from arch/arc/include/uapi/asm/byteorder.h:14,
                    from include/asm-generic/bitops/le.h:6,
                    from arch/arc/include/asm/bitops.h:192,
                    from include/linux/bitops.h:68,
                    from include/linux/kernel.h:23,
                    from drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:8:
   In function '__fswab32',
       inlined from 'brcmf_fil_iovar_int_get' at drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil.h:123:19,
       inlined from 'brcmf_setup_wiphybands' at drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:7359:8:
>> arch/arc/include/uapi/asm/swab.h:28:9: warning: 'txchain' is used uninitialized [-Wuninitialized]
      28 |         __asm__(                        \
         |         ^~~~~~~
   include/uapi/linux/swab.h:60:16: note: in expansion of macro '__arch_swab32'
      60 |         return __arch_swab32(val);
         |                ^~~~~~~~~~~~~
   drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c: In function 'brcmf_setup_wiphybands':
   drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:7316:13: note: 'txchain' was declared here
    7316 |         u32 txchain;
         |             ^~~~~~~


vim +/txchain +28 arch/arc/include/uapi/asm/swab.h

ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  24  
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  25  #define __arch_swab32(x)		\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  26  ({					\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  27  	unsigned int tmp = x;		\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18 @28  	__asm__(			\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  29  	"	swape	%0, %1	\n"	\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  30  	: "=r" (tmp)			\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  31  	: "r" (tmp));			\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  32  	tmp;				\
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  33  })
ca15c8ecd588dd arch/arc/include/asm/swab.h Vineet Gupta 2013-01-18  34  

:::::: The code at line 28 was first introduced by commit
:::::: ca15c8ecd588dda4377d18d6d27bc1e87b4177cb ARC: Checksum/byteorder/swab routines

:::::: TO: Vineet Gupta <vgupta@synopsys.com>
:::::: CC: Vineet Gupta <vgupta@synopsys.com>

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