[arm:cex7 88/106] arch/c6x/include/uapi/asm/swab.h:21:2: warning: 'px_is' may be used uninitialized in this function

[arm:cex7 88/106] arch/c6x/include/uapi/asm/swab.h:21:2: warning: 'px_is' may be used uninitialized in this function

[kbuild test robot]

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tree:   git://git.armlinux.org.uk/~rmk/linux-arm.git cex7
head:   96bd73e4644e76befe9ab998e070a679ae08388c
commit: 04d1ec3ed831580aadbdac12b36b6158ad80dad4 [88/106] ahci: qoriq: workaround for errata A-379364 on lx2160a
config: c6x-allyesconfig (attached as .config)
compiler: c6x-elf-gcc (GCC) 9.3.0
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
        git checkout 04d1ec3ed831580aadbdac12b36b6158ad80dad4
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=c6x 

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

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 >>, old ones prefixed by <<):

In file included from drivers/ata/ahci_qoriq.c:19:
drivers/ata/ahci.h:384:16: warning: initialized field overwritten [-Woverride-init]
384 |  .can_queue  = AHCI_MAX_CMDS,            |                ^~~~~~~~~~~~~
drivers/ata/ahci_qoriq.c:304:2: note: in expansion of macro 'AHCI_SHT'
304 |  AHCI_SHT(DRV_NAME),
|  ^~~~~~~~
drivers/ata/ahci.h:384:16: note: (near initialization for 'ahci_qoriq_sht.can_queue')
384 |  .can_queue  = AHCI_MAX_CMDS,            |                ^~~~~~~~~~~~~
drivers/ata/ahci_qoriq.c:304:2: note: in expansion of macro 'AHCI_SHT'
304 |  AHCI_SHT(DRV_NAME),
|  ^~~~~~~~
drivers/ata/ahci.h:388:17: warning: initialized field overwritten [-Woverride-init]
388 |  .sdev_attrs  = ahci_sdev_attrs
|                 ^~~~~~~~~~~~~~~
drivers/ata/ahci_qoriq.c:304:2: note: in expansion of macro 'AHCI_SHT'
304 |  AHCI_SHT(DRV_NAME),
|  ^~~~~~~~
drivers/ata/ahci.h:388:17: note: (near initialization for 'ahci_qoriq_sht.sdev_attrs')
388 |  .sdev_attrs  = ahci_sdev_attrs
|                 ^~~~~~~~~~~~~~~
drivers/ata/ahci_qoriq.c:304:2: note: in expansion of macro 'AHCI_SHT'
304 |  AHCI_SHT(DRV_NAME),
|  ^~~~~~~~
In file included from include/uapi/linux/swab.h:8,
from include/linux/swab.h:5,
from include/uapi/linux/byteorder/big_endian.h:13,
from include/linux/byteorder/big_endian.h:5,
from arch/c6x/include/uapi/asm/byteorder.h:8,
from arch/c6x/include/asm/bitops.h:14,
from include/linux/bitops.h:29,
from include/linux/kernel.h:12,
from drivers/ata/ahci_qoriq.c:9:
drivers/ata/ahci_qoriq.c: In function 'ahci_qoriq_hardreset':
>> arch/c6x/include/uapi/asm/swab.h:21:2: warning: 'px_is' may be used uninitialized in this function [-Wmaybe-uninitialized]
21 |  asm("swap4 .l1 %0,%0n"
|  ^~~
drivers/ata/ahci_qoriq.c:229:14: note: 'px_is' was declared here
229 |  u32 px_cmd, px_is, px_val;
|              ^~~~~
In file included from include/uapi/linux/swab.h:8,
from include/linux/swab.h:5,
from include/uapi/linux/byteorder/big_endian.h:13,
from include/linux/byteorder/big_endian.h:5,
from arch/c6x/include/uapi/asm/byteorder.h:8,
from arch/c6x/include/asm/bitops.h:14,
from include/linux/bitops.h:29,
from include/linux/kernel.h:12,
from drivers/ata/ahci_qoriq.c:9:
>> arch/c6x/include/uapi/asm/swab.h:21:2: warning: 'px_cmd' may be used uninitialized in this function [-Wmaybe-uninitialized]
21 |  asm("swap4 .l1 %0,%0n"
|  ^~~
drivers/ata/ahci_qoriq.c:229:6: note: 'px_cmd' was declared here
229 |  u32 px_cmd, px_is, px_val;
|      ^~~~~~

vim +/px_is +21 arch/c6x/include/uapi/asm/swab.h

a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  18  
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  19  static inline __attribute_const__ __u32 __c6x_swab32(__u32 val)
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  20  {
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04 @21  	asm("swap4 .l1 %0,%0\n"
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  22  	    "swap2 .l1 %0,%0\n"
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  23  	    : "+a"(val));
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  24  	return val;
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  25  }
a7f626c1948ab61 arch/c6x/include/asm/swab.h Aurelien Jacquiot 2011-10-04  26  

:::::: The code at line 21 was first introduced by commit
:::::: a7f626c1948ab6178d2338831c5ffea7385e9f7f C6X: headers

:::::: TO: Aurelien Jacquiot <a-jacquiot@ti.com>
:::::: CC: Mark Salter <msalter@redhat.com>

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

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