Re: [net-next, 1/2] enetc: Configure the Time-Aware Scheduler via tc-taprio offload

Hi Po,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]
[also build test WARNING on v5.4-rc7 next-20191111]
[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/Po-Liu/enetc-Configure-the-Time-Aware-Scheduler-via-tc-taprio-offload/20191112-193235
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git ca22d6977b9b4ab0fd2e7909b57e32ba5b95046f
config: s390-allmodconfig (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
        # 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 <redacted>

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   In file included from arch/s390/include/asm/io.h:76:0,
                    from include/linux/io.h:13,
                    from include/linux/pci.h:39,
                    from drivers/net/ethernet/freescale/enetc/enetc.h:5,
                    from drivers/net/ethernet/freescale/enetc/enetc_qos.c:4:
   drivers/net/ethernet/freescale/enetc/enetc_qos.c: In function 'enetc_setup_tc_taprio':

quoted

include/asm-generic/io.h:735:19: warning: 'temp' may be used uninitialized in this function [-Wmaybe-uninitialized]

    #define iowrite32 iowrite32
                      ^~~~~~~~~
   drivers/net/ethernet/freescale/enetc/enetc_qos.c:25:6: note: 'temp' was declared here
     u32 temp;
         ^~~~
--
   In file included from arch/s390/include/asm/io.h:76:0,
                    from include/linux/io.h:13,
                    from include/linux/pci.h:39,
                    from drivers/net//ethernet/freescale/enetc/enetc.h:5,
                    from drivers/net//ethernet/freescale/enetc/enetc_qos.c:4:
   drivers/net//ethernet/freescale/enetc/enetc_qos.c: In function 'enetc_setup_tc_taprio':

quoted

include/asm-generic/io.h:735:19: warning: 'temp' may be used uninitialized in this function [-Wmaybe-uninitialized]

    #define iowrite32 iowrite32
                      ^~~~~~~~~
   drivers/net//ethernet/freescale/enetc/enetc_qos.c:25:6: note: 'temp' was declared here
     u32 temp;
         ^~~~

vim +/temp +735 include/asm-generic/io.h

9216efafc52ff9 Thierry Reding 2014-10-01  733  
9216efafc52ff9 Thierry Reding 2014-10-01  734  #ifndef iowrite32
9216efafc52ff9 Thierry Reding 2014-10-01 @735  #define iowrite32 iowrite32
9216efafc52ff9 Thierry Reding 2014-10-01  736  static inline void iowrite32(u32 value, volatile void __iomem *addr)
9216efafc52ff9 Thierry Reding 2014-10-01  737  {
9216efafc52ff9 Thierry Reding 2014-10-01  738  	writel(value, addr);
9216efafc52ff9 Thierry Reding 2014-10-01  739  }
9216efafc52ff9 Thierry Reding 2014-10-01  740  #endif
9216efafc52ff9 Thierry Reding 2014-10-01  741  

:::::: The code at line 735 was first introduced by commit
:::::: 9216efafc52ff99e9351ef60de5fcafc2bc8adb6 asm-generic/io.h: Reconcile I/O accessor overrides

:::::: TO: Thierry Reding [off-list ref]
:::::: CC: Thierry Reding [off-list ref]

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0-DAY kernel test infrastructure                 Open Source Technology Center
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