[s390:zlib 5/5] lib/zlib_dfltcc/dfltcc_deflate.c:20:36: warning: suggest parentheses around comparison in operand of '&'

[kbuild test robot <lkp@xxxxxxxxx>]

tree:   https://kernel.googlesource.com/pub/scm/linux/kernel/git/s390/linux.git zlib
head:   cd020aae5488f8576ee8c289b7c32fb4a05f60bb
commit: cd020aae5488f8576ee8c289b7c32fb4a05f60bb [5/5] Add dfltcc= kernel command line parameter
config: s390-debug_defconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout cd020aae5488f8576ee8c289b7c32fb4a05f60bb
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=s390 

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

All warnings (new ones prefixed by >>):

   lib/zlib_dfltcc/dfltcc_deflate.c: In function 'dfltcc_can_deflate':
>> lib/zlib_dfltcc/dfltcc_deflate.c:20:36: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
        if (kernel_zlib_dfltcc_support & ZLIB_DFLTCC_DEFLATE_ENABLED == 0)
                                       ^

vim +20 lib/zlib_dfltcc/dfltcc_deflate.c

     8	
     9	/*
    10	 * Compress.
    11	 */
    12	int dfltcc_can_deflate(
    13	    z_streamp strm
    14	)
    15	{
    16	    deflate_state *state = (deflate_state *)strm->state;
    17	    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
    18	
    19	    /* Check for kernel dfltcc command line parameter */
  > 20	    if (kernel_zlib_dfltcc_support & ZLIB_DFLTCC_DEFLATE_ENABLED == 0)
    21	        return 0;
    22	
    23	    /* Unsupported compression settings */
    24	    if (!dfltcc_are_params_ok(state->level, state->w_bits, state->strategy,
    25	                              dfltcc_state->level_mask))
    26	        return 0;
    27	
    28	    /* Unsupported hardware */
    29	    if (!is_bit_set(dfltcc_state->af.fns, DFLTCC_GDHT) ||
    30	            !is_bit_set(dfltcc_state->af.fns, DFLTCC_CMPR) ||
    31	            !is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0))
    32	        return 0;
    33	
    34	    return 1;
    35	}
    36	

---
0-DAY kernel test infrastructure                Open Source Technology Center
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