# git rev-parse -q --verify 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b^{commit}
70b20dd7f897c6c14ab9e0d8400aed520ab5f09b
already have revision, skipping fetch
# git checkout -q -f -B kisskb 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b
# git clean -qxdf
# < git log -1
# commit 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Wed Aug 15 19:08:10 2018 -0700
# 
#     ALSA: update dell-wmi mic-mute registration to new world order
#     
#     Commit c647f806b8c2 ("ALSA: hda - Allow multiple ADCs for mic mute LED
#     controls") changed the return value of the snd_hda_gen_add_micmute_led()
#     without actually updating the callers.
#     
#     Admittedly, almost no callers actually cared about the return value.
#     But one call site very much did: the Dell wmi code.  It would see the
#     registration return zero, which _used_ to mean "failed" but now means
#     "success", and clear the dell_micmute_led_set_func pointer.
#     
#     End result: the successful registration would end up calling the Dell
#     code that thought it had all failed, and call through a NULL pointer.
#     
#     To make matters worse, it ends up being a tail-call, and with the
#     retpoline sequence you don't even see the caller (dell_micmute_update())
#     in the stack trace, so the error ended up way less obvious than it
#     should have been.
#     
#     Fixes: c647f806b8c2 "ALSA: hda - Allow multiple ADCs for mic mute LED controls"
#     Cc: Takashi Iwai <tiwai@suse.de>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-gcc --version
# < git log --format=%s --max-count=1 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b
# < make -s -j 10 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allnoconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  allnoconfig

WARNING: unmet direct dependencies detected for COMPAT_BINFMT_ELF
  Depends on [n]: COMPAT [=y] && BINFMT_ELF [=n]
  Selected by [y]:
  - COMPAT [=y] && SPARC64 [=y]

WARNING: unmet direct dependencies detected for COMPAT_BINFMT_ELF
  Depends on [n]: COMPAT [=y] && BINFMT_ELF [=n]
  Selected by [y]:
  - COMPAT [=y] && SPARC64 [=y]
# make -s -j 10 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allnoconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  
<stdin>:1332:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp]
<stdin>:1335:2: warning: #warning syscall rseq not implemented [-Wcpp]
  kernel: arch/sparc/boot/image is ready
  kernel: arch/sparc/boot/zImage is ready
Completed OK
# rm -rf /kisskb/build/linus_sparc64-allnoconfig_sparc64
# Build took: 0:00:24.228888