include/asm-generic/mmiowb.h:56:9: sparse: sparse: context imbalance in 'ep0_write' - unexpected unlock

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   da2968ff879b9e74688cdc658f646971991d2c56
commit: df8df5e4bc37e39010cfdf5d50cf726fe08aae5b usb: get rid of 'choice' for legacy gadget drivers
date:   5 months ago
config: powerpc-randconfig-s032-20200821 (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.2-191-g10164920-dirty
        git checkout df8df5e4bc37e39010cfdf5d50cf726fe08aae5b
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=powerpc 

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


sparse warnings: (new ones prefixed by >>)

   drivers/usb/gadget/legacy/inode.c: note: in included file (through arch/powerpc/include/asm/mmiowb.h, include/linux/spinlock.h, include/linux/seqlock.h, ...):
>> include/asm-generic/mmiowb.h:56:9: sparse: sparse: context imbalance in 'ep0_write' - unexpected unlock

# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=df8df5e4bc37e39010cfdf5d50cf726fe08aae5b
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout df8df5e4bc37e39010cfdf5d50cf726fe08aae5b
vim +/ep0_write +56 include/asm-generic/mmiowb.h

d1be6a28b13ce6 Will Deacon 2019-02-22  46  
d1be6a28b13ce6 Will Deacon 2019-02-22  47  static inline void mmiowb_spin_unlock(void)
d1be6a28b13ce6 Will Deacon 2019-02-22  48  {
d1be6a28b13ce6 Will Deacon 2019-02-22  49  	struct mmiowb_state *ms = __mmiowb_state();
d1be6a28b13ce6 Will Deacon 2019-02-22  50  
d1be6a28b13ce6 Will Deacon 2019-02-22  51  	if (unlikely(ms->mmiowb_pending)) {
d1be6a28b13ce6 Will Deacon 2019-02-22  52  		ms->mmiowb_pending = 0;
d1be6a28b13ce6 Will Deacon 2019-02-22  53  		mmiowb();
d1be6a28b13ce6 Will Deacon 2019-02-22  54  	}
d1be6a28b13ce6 Will Deacon 2019-02-22  55  
d1be6a28b13ce6 Will Deacon 2019-02-22 @56  	ms->nesting_count--;

:::::: The code at line 56 was first introduced by commit
:::::: d1be6a28b13ce6d1bc42bf9b6a9454c65839225b asm-generic/mmiowb: Add generic implementation of mmiowb() tracking

:::::: TO: Will Deacon <will.deacon@xxxxxxx>
:::::: CC: Will Deacon <will.deacon@xxxxxxx>

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

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