# git rev-parse -q --verify 4b820e167bf6f410ace479d8df5b15a574000e75^{commit}
4b820e167bf6f410ace479d8df5b15a574000e75
already have revision, skipping fetch
# git checkout -q -f -B kisskb 4b820e167bf6f410ace479d8df5b15a574000e75
# git clean -qxdf
# < git log -1
# commit 4b820e167bf6f410ace479d8df5b15a574000e75
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Fri Jul 2 22:05:52 2021 -0700
# 
#     Revert "ALSA: usb-audio: Reduce latency at playback start"
#     
#     This reverts commit 9ce650a75a3b262c90789b42aedee8fc2ee04d53.
#     
#     This commit causes watchdog lockups on my machine, and while I have no
#     idea what the cause is, it bisected right to this commit, and reverting
#     the change promptly fixes it.
#     
#     At least occasionally one of the watchdog call traces was
#     
#       Call Trace:
#         _raw_spin_lock_irqsave+0x35/0x40
#         snd_pcm_period_elapsed+0x1b/0xa0 [snd_pcm]
#         snd_usb_endpoint_start+0x1a0/0x3c0 [snd_usb_audio]
#         start_endpoints+0x23/0x90 [snd_usb_audio]
#         snd_usb_substream_playback_trigger+0x7b/0x1a0 [snd_usb_audio]
#         snd_pcm_common_ioctl+0x1c44/0x2360 [snd_pcm]
#         snd_pcm_ioctl+0x2e/0x40 [snd_pcm]
#         __se_sys_ioctl+0x72/0xc0
#         do_syscall_64+0x4c/0xa0
#         entry_SYSCALL_64_after_hwframe+0x44/0xae
#     
#     so presumably it's a locking error on that substream spinlock that
#     snd_pcm_period_elapsed() takes.  But at this point I just want to have a
#     working system so that I can continue the merge window work tomorrow.
#     
#     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
# < /opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-ld --version
# < git log --format=%s --max-count=1 4b820e167bf6f410ace479d8df5b15a574000e75
# < make -s -j 24 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allmodconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  allmodconfig
# Added to kconfig CONFIG_BUILD_DOCSRC=n
# Added to kconfig CONFIG_HAVE_FTRACE_MCOUNT_RECORD=n
# Added to kconfig CONFIG_SAMPLES=n
# Added to kconfig CONFIG_MODULE_SIG=n
# < make -s -j 24 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allmodconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  help
# make -s -j 24 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allmodconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  olddefconfig
# make -s -j 24 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allmodconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
In file included from /kisskb/src/include/linux/kernel.h:16:0,
                 from /kisskb/src/include/linux/list.h:9,
                 from /kisskb/src/include/linux/module.h:12,
                 from /kisskb/src/drivers/gpu/drm/ttm/ttm_pool.c:34:
/kisskb/src/drivers/gpu/drm/ttm/ttm_pool.c: In function 'ttm_pool_alloc':
/kisskb/src/include/linux/minmax.h:20:28: warning: comparison of distinct pointer types lacks a cast
  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                            ^
/kisskb/src/include/linux/minmax.h:26:4: note: in expansion of macro '__typecheck'
   (__typecheck(x, y) && __no_side_effects(x, y))
    ^
/kisskb/src/include/linux/minmax.h:36:24: note: in expansion of macro '__safe_cmp'
  __builtin_choose_expr(__safe_cmp(x, y), \
                        ^
/kisskb/src/include/linux/minmax.h:45:19: note: in expansion of macro '__careful_cmp'
 #define min(x, y) __careful_cmp(x, y, <)
                   ^
/kisskb/src/drivers/gpu/drm/ttm/ttm_pool.c:386:15: note: in expansion of macro 'min'
  for (order = min(MAX_ORDER - 1UL, __fls(num_pages)); num_pages;
               ^
/kisskb/src/drivers/input/joystick/analog.c:160:2: warning: #warning Precise timer not defined for this architecture. [-Wcpp]
 #warning Precise timer not defined for this architecture.
  ^
In file included from <command-line>:0:0:
/kisskb/src/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c: In function 'ifh_encode_bitfield':
/kisskb/src/include/linux/compiler_types.h:328:38: error: call to '__compiletime_assert_418' declared with attribute error: Unsupported width, must be <= 40
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
                                      ^
/kisskb/src/include/linux/compiler_types.h:309:4: note: in definition of macro '__compiletime_assert'
    prefix ## suffix();    \
    ^
/kisskb/src/include/linux/compiler_types.h:328:2: note: in expansion of macro '_compiletime_assert'
  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
  ^
/kisskb/src/drivers/net/ethernet/microchip/sparx5/sparx5_netdev.c:28:2: note: in expansion of macro 'compiletime_assert'
  compiletime_assert(width <= 40, "Unsupported width, must be <= 40");
  ^
make[6]: *** [/kisskb/src/scripts/Makefile.build:273: drivers/net/ethernet/microchip/sparx5/sparx5_netdev.o] Error 1
make[5]: *** [/kisskb/src/scripts/Makefile.build:516: drivers/net/ethernet/microchip/sparx5] Error 2
make[4]: *** [/kisskb/src/scripts/Makefile.build:516: drivers/net/ethernet/microchip] Error 2
make[4]: *** Waiting for unfinished jobs....
make[3]: *** [/kisskb/src/scripts/Makefile.build:516: drivers/net/ethernet] Error 2
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [/kisskb/src/scripts/Makefile.build:516: drivers/net] Error 2
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [/kisskb/src/Makefile:1847: drivers] Error 2
make: *** [Makefile:215: __sub-make] Error 2
Command 'make -s -j 24 ARCH=sparc64 O=/kisskb/build/linus_sparc64-allmodconfig_sparc64 CROSS_COMPILE=/opt/cross/kisskb/br-sparc64-full-2016.08-613-ge98b4dd/bin/sparc64-linux-  ' returned non-zero exit status 2
# rm -rf /kisskb/build/linus_sparc64-allmodconfig_sparc64
# Build took: 0:18:43.479528