Re: [PATCH] x86: Optimise x86 IP checksum code

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

Hi David,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tip/auto-latest]
[also build test WARNING on tip/x86/core linus/master v5.4 next-20191202]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/David-Laight/x86-Optimise-x86-IP-checksum-code/20191203-211313
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git e445033e58108a9891abfbc0dea90b066a75e4a9
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.1-91-g817270f-dirty
        make ARCH=x86_64 allmodconfig
        make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

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


sparse warnings: (new ones prefixed by >>)

>> arch/x86/lib/csum-partial_64.c:141:23: sparse: sparse: incorrect type in return expression (different base types) @@    expected restricted __wsum @@    got icted __wsum @@
>> arch/x86/lib/csum-partial_64.c:141:23: sparse:    expected restricted __wsum
>> arch/x86/lib/csum-partial_64.c:141:23: sparse:    got unsigned int

vim +141 arch/x86/lib/csum-partial_64.c

   126	
   127	/*
   128	 * computes the checksum of a memory block at buff, length len,
   129	 * and adds in "sum" (32-bit)
   130	 *
   131	 * returns a 32-bit number suitable for feeding into itself
   132	 * or csum_tcpudp_magic
   133	 *
   134	 * this function must be called with even lengths, except
   135	 * for the last fragment, which may be odd
   136	 *
   137	 * it's best to have buff aligned on a 64-bit boundary
   138	 */
   139	__wsum csum_partial(const void *buff, int len, __wsum sum)
   140	{
 > 141		return do_csum(buff, len, (__force u32)sum);
   142	}
   143	EXPORT_SYMBOL(csum_partial);
   144	

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