[linux-next:master 6411/6654] drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3014:7: warning: variable 'link' is used uninitialized whenever 'if' condition is false

[linux-next:master 6411/6654] drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3014:7: warning: variable 'link' is used uninitialized whenever 'if' condition is false

[kernel test robot]

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   7ce53e3a447bced7b85ed181c4d027e93c062e07
commit: 36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd [6411/6654] net: mvpp2: restructure "link status" interrupt handling
config: powerpc64-randconfig-r011-20200909 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0a5dc7effb191eff740e0e7ae7bd8e1f6bdb3ad9)
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 powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        git checkout 36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 

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 >>):

>> drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3014:7: warning: variable 'link' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
                   if (val & MVPP22_XLG_STATUS_LINK_UP)
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3016:31: note: uninitialized use occurs here
                   mvpp2_isr_handle_link(port, link);
                                               ^~~~
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3014:3: note: remove the 'if' if its condition is always true
                   if (val & MVPP22_XLG_STATUS_LINK_UP)
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3008:11: note: initialize the variable 'link' to silence this warning
           bool link;
                    ^
                     = 0
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3031:8: warning: variable 'link' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
                           if (val & MVPP2_GMAC_STATUS0_LINK_UP)
                               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3033:32: note: uninitialized use occurs here
                           mvpp2_isr_handle_link(port, link);
                                                       ^~~~
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3031:4: note: remove the 'if' if its condition is always true
                           if (val & MVPP2_GMAC_STATUS0_LINK_UP)
                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3022:11: note: initialize the variable 'link' to silence this warning
           bool link;
                    ^
                     = 0
   drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:6785:36: warning: unused variable 'mvpp2_acpi_match' [-Wunused-const-variable]
   static const struct acpi_device_id mvpp2_acpi_match[] = {
                                      ^
   3 warnings generated.

# https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd
git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git fetch --no-tags linux-next master
git checkout 36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd
vim +3014 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3005  
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3006  static void mvpp2_isr_handle_xlg(struct mvpp2_port *port)
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3007  {
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3008  	bool link;
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3009  	u32 val;
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01  3010  
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01  3011  	val = readl(port->base + MVPP22_XLG_INT_STAT);
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01  3012  	if (val & MVPP22_XLG_INT_STAT_LINK) {
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01  3013  		val = readl(port->base + MVPP22_XLG_STATUS);
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01 @3014  		if (val & MVPP22_XLG_STATUS_LINK_UP)
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01  3015  			link = true;
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3016  		mvpp2_isr_handle_link(port, link);
fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c            Antoine Tenart 2017-09-01  3017  	}
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3018  }
36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King   2020-09-09  3019  

:::::: The code at line 3014 was first introduced by commit
:::::: fd3651b2ab66de177ad0d51c239af260a764b9f1 net: mvpp2: use the GoP interrupt for link status changes

:::::: TO: Antoine Tenart <antoine.tenart@free-electrons.com>
:::::: CC: David S. Miller <davem@davemloft.net>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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