arch/arm/mach-s3c/s3c24xx.c:177:16: warning: variable 'tmp' set but not used

From: kernel test robot
Date: Sun Aug 15 2021 - 04:18:04 EST


Hi Arnd,

First bad commit (maybe != root cause):

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 0aa78d17099b04fd9d36fe338af48ad6fe2d7fca
commit: 71b9114d2c13a648fbe6523dd859e611c316ad90 ARM: s3c: move into a common directory
date: 12 months ago
config: arm-randconfig-r023-20210815 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 1f7b25ea76a925aca690da28de9d78db7ca99d0c)
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
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=71b9114d2c13a648fbe6523dd859e611c316ad90
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 71b9114d2c13a648fbe6523dd859e611c316ad90
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm

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

All warnings (new ones prefixed by >>):

>> arch/arm/mach-s3c/s3c24xx.c:177:16: warning: variable 'tmp' set but not used [-Wunused-but-set-variable]
unsigned long tmp = 0;
^
1 warning generated.
--
>> arch/arm/mach-s3c/gpio-samsung.c:1309:14: warning: no previous prototype for function 's3c2410_modify_misccr' [-Wmissing-prototypes]
unsigned int s3c2410_modify_misccr(unsigned int clear, unsigned int change)
^
arch/arm/mach-s3c/gpio-samsung.c:1309:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
unsigned int s3c2410_modify_misccr(unsigned int clear, unsigned int change)
^
static
1 warning generated.


vim +/tmp +177 arch/arm/mach-s3c/s3c24xx.c

68d9ab394f06f9 arch/arm/mach-s3c2410/cpu.c Ben Dooks 2006-06-24 174
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 175 static void s3c24xx_default_idle(void)
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 176 {
813f13e7d6ad23 arch/arm/mach-s3c24xx/common.c Cong Ding 2013-01-18 @177 unsigned long tmp = 0;
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 178 int i;
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 179
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 180 /* idle the system by using the idle mode which will wait for an
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 181 * interrupt to happen before restarting the system.
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 182 */
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 183
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 184 /* Warning: going into idle state upsets jtag scanning */
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 185
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 186 __raw_writel(__raw_readl(S3C2410_CLKCON) | S3C2410_CLKCON_IDLE,
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 187 S3C2410_CLKCON);
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 188
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 189 /* the samsung port seems to do a loop and then unset idle.. */
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 190 for (i = 0; i < 50; i++)
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 191 tmp += __raw_readl(S3C2410_CLKCON); /* ensure loop not optimised out */
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 192
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 193 /* this bit is not cleared on re-start... */
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 194
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 195 __raw_writel(__raw_readl(S3C2410_CLKCON) & ~S3C2410_CLKCON_IDLE,
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 196 S3C2410_CLKCON);
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 197 }
92311272c1a514 arch/arm/plat-s3c24xx/cpu.c Nicolas Pitre 2011-08-03 198

:::::: The code at line 177 was first introduced by commit
:::::: 813f13e7d6ad239bb1003041f4cfae13ae27b14d ARM: S3C24XX: fix uninitialized variable warning

:::::: TO: Cong Ding <dinggnu@xxxxxxxxx>
:::::: CC: Kukjin Kim <kgene.kim@xxxxxxxxxxx>

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

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