# git rev-parse -q --verify 0f1a7b3fac0583083ca19d4de47403511ced3521^{commit}
0f1a7b3fac0583083ca19d4de47403511ced3521
already have revision, skipping fetch
# git checkout -q -f -B kisskb 0f1a7b3fac0583083ca19d4de47403511ced3521
# git clean -qxdf
# < git log -1
# commit 0f1a7b3fac0583083ca19d4de47403511ced3521
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Wed Oct 2 16:16:07 2019 -0700
# 
#     timer-of: don't use conditional expression with mixed 'void' types
#     
#     Randy Dunlap reports on the sparse list that sparse warns about this
#     expression:
#     
#             of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) :
#                     free_irq(of_irq->irq, clkevt);
#     
#     and honestly, sparse is correct to warn.  The return type of
#     free_percpu_irq() is 'void', while free_irq() returns a 'const void *'
#     that is the devname argument passed in to the request_irq().
#     
#     You can't mix a void type with a non-void types in a conditional
#     expression according to the C standard.  It so happens that gcc seems to
#     accept it - and the resulting type of the expression is void - but
#     there's really no reason for the kernel to have this kind of
#     non-standard expression with no real upside.
#     
#     The natural way to write that expression is with an if-statement:
#     
#             if (of_irq->percpu)
#                     free_percpu_irq(of_irq->irq, clkevt);
#             else
#                     free_irq(of_irq->irq, clkevt);
#     
#     which is more legible anyway.
#     
#     I'm not sure why that timer-of code seems to have this odd pattern.  It
#     does the same at allocation time, but at least there the types match,
#     and it makes sense as an expression.
#     
#     Reported-by: Randy Dunlap <rdunlap@infradead.org>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa64-linux/bin/hppa64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa64-linux/bin/hppa64-linux-ld --version
# < git log --format=%s --max-count=1 0f1a7b3fac0583083ca19d4de47403511ced3521
# < make -s -j 10 ARCH=parisc O=/kisskb/build/linus_a500_defconfig_parisc64 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa64-linux/bin/hppa64-linux-  a500_defconfig
# make -s -j 10 ARCH=parisc O=/kisskb/build/linus_a500_defconfig_parisc64 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/hppa64-linux/bin/hppa64-linux-  
In file included from /kisskb/src/arch/parisc/include/asm/atomic.h:10,
                 from /kisskb/src/include/linux/atomic.h:7,
                 from /kisskb/src/arch/parisc/include/asm/bitops.h:13,
                 from /kisskb/src/include/linux/bitops.h:19,
                 from /kisskb/src/include/linux/kernel.h:12,
                 from /kisskb/src/include/linux/list.h:9,
                 from /kisskb/src/include/linux/preempt.h:11,
                 from /kisskb/src/include/linux/spinlock.h:51,
                 from /kisskb/src/include/linux/seqlock.h:36,
                 from /kisskb/src/include/linux/time.h:6,
                 from /kisskb/src/fs/nfs/read.c:11:
/kisskb/src/fs/nfs/read.c: In function 'nfs_read_completion':
/kisskb/src/arch/parisc/include/asm/cmpxchg.h:48:3: warning: value computed is not used [-Wunused-value]
  ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
  ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/kisskb/src/fs/nfs/read.c:196:5: note: in expansion of macro 'xchg'
     xchg(&nfs_req_openctx(req)->error, error);
     ^~~~
/kisskb/src/fs/nfs/read.c: In function 'nfs_readpage':
/kisskb/src/arch/parisc/include/asm/cmpxchg.h:48:3: warning: value computed is not used [-Wunused-value]
  ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
  ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/kisskb/src/fs/nfs/read.c:352:2: note: in expansion of macro 'xchg'
  xchg(&ctx->error, 0);
  ^~~~
In file included from /kisskb/src/arch/parisc/include/asm/atomic.h:10,
                 from /kisskb/src/include/linux/atomic.h:7,
                 from /kisskb/src/arch/parisc/include/asm/bitops.h:13,
                 from /kisskb/src/include/linux/bitops.h:19,
                 from /kisskb/src/include/linux/kernel.h:12,
                 from /kisskb/src/include/linux/list.h:9,
                 from /kisskb/src/include/linux/module.h:9,
                 from /kisskb/src/drivers/scsi/scsi_debug.c:18:
/kisskb/src/drivers/scsi/scsi_debug.c: In function 'resp_start_stop':
/kisskb/src/arch/parisc/include/asm/cmpxchg.h:48:3: warning: value computed is not used [-Wunused-value]
  ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
/kisskb/src/arch/parisc/include/asm/atomic.h:78:30: note: in expansion of macro 'xchg'
 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
                              ^~~~
/kisskb/src/drivers/scsi/scsi_debug.c:1618:2: note: in expansion of macro 'atomic_xchg'
  atomic_xchg(&devip->stopped, stop);
  ^~~~~~~~~~~
Completed OK
# rm -rf /kisskb/build/linus_a500_defconfig_parisc64
# Build took: 0:01:30.955905