Problem
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systemd-udevd taking 100% cpu.
Even failing to power off Ubuntu. (screen shut down, machine power stayed on. Has to long press power button to shuf down Ubuntu1604LTS.)
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Investigating
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Seeing this i2c related kernel error.
"i2c i2c-1: sendbytes: NAK bailout."
It's reported previously. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1675540
This bug still exists and looks like it was identified as part of the Nouveau video driver, experienced now with Ubuntu 16.10.
$dmesg indicated that it's when calling cx88_audio_pci_driver_init
continuously time out due to i2c error.
- pci_audio_driver loading hang.....
[ 15.080129] i2c i2c-13: sendbytes: error -110
[ 16.287687] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 16.308070] ip6_tables: (C) 2000-2006 Netfilter Core Team
[ 244.171444] INFO: task systemd-udevd:325 blocked for more than 120 seconds.
[ 244.171451] Not tainted 4.13.0-32-generic #35~16.04.1-Ubuntu
[ 244.171453] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 244.171456] systemd-udevd D 0 325 278 0x00000004
[ 244.171460] Call Trace:
[ 244.171470] __schedule+0x3c2/0x890
[ 244.171474] schedule+0x36/0x80
[ 244.171477] schedule_preempt_disabled+0xe/0x10
[ 244.171480] __mutex_lock.isra.2+0x2ae/0x4e0
[ 244.171487] ? driver_probe_device+0x450/0x450
[ 244.171490] __mutex_lock_slowpath+0x13/0x20
[ 244.171492] ? __mutex_lock_slowpath+0x13/0x20
[ 244.171495] mutex_lock+0x2f/0x40
[ 244.171497] __driver_attach+0x5d/0xf0
[ 244.171500] ? driver_probe_device+0x450/0x450
[ 244.171503] bus_for_each_dev+0x6c/0xc0
[ 244.171506] driver_attach+0x1e/0x20
[ 244.171508] bus_add_driver+0x1f4/0x270
[ 244.171512] ? 0xffffffffc00a6000
[ 244.171515] driver_register+0x60/0xe0
[ 244.171517] ? 0xffffffffc00a6000
[ 244.171522] __pci_register_driver+0x4c/0x50
[ 244.171528] cx88_audio_pci_driver_init+0x1e/0x1000 [cx88_alsa] ..............
[ 244.171532] do_one_initcall+0x53/0x1b0
[ 244.171536] ? __vunmap+0x81/0xb0
[ 244.171540] ? kmem_cache_alloc_trace+0x152/0x1b0
[ 244.171543] ? kfree+0x162/0x170
[ 244.171548] do_init_module+0x5f/0x209
[ 244.171551] load_module+0x1961/0x1d60
[ 244.171556] ? ima_post_read_file+0x7d/0xa0
[ 244.171561] SYSC_finit_module+0xe5/0x120
[ 244.171564] ? SYSC_finit_module+0xe5/0x120
[ 244.171568] SyS_finit_module+0xe/0x10
[ 244.171572] entry_SYSCALL_64_fastpath+0x33/0xa3
[ 244.171575] RIP: 0033:0x7ff05dcda4d9
[ 244.171576] RSP: 002b:00007ffe319d70c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000139
[ 244.171579] RAX: ffffffffffffffda RBX: 00005627dc1ac890 RCX: 00007ff05dcda4d9
[ 244.171581] RDX: 0000000000000000 RSI: 00005627dc1b8450 RDI: 0000000000000007
[ 244.171583] RBP: 00005627dc1b8450 R08: 0000000000000000 R09: 0000000000000011
[ 244.171584] R10: 0000000000000007 R11: 0000000000000202 R12: 0000000000000000
[ 244.171586] R13: 00005627dc1cec00 R14: 0000000000020000 R15: 0000000000000000
Tried loading old kernel back to 4-Feb. Problem still exist.
qyang@Ubuntu1604LTS:~$ ll /lib/modules/
total 24K
drwxr-xr-x 5 root root 4.0K Jun 20 2017 4.8.0-56-generic/
drwxr-xr-x 23 root root 4.0K Feb 4 07:36 ../
drwxr-xr-x 5 root root 4.0K Feb 4 07:40 4.13.0-32-generic/
drwxr-xr-x 5 root root 4.0K Feb 25 09:50 4.13.0-36-generic/
drwxr-xr-x 6 root root 4.0K Mar 15 22:19 ./
drwxr-xr-x 5 root root 4.0K Mar 15 22:48 4.13.0-37-generic/
Check cx88 releated hardware drivers.
qyang@Ubuntu1604LTS:~$ lsmod |grep cx88
cx88_alsa 20480 1
snd_pcm 98304 5 snd_hda_intel,snd_hda_codec,cx88_alsa,snd_hda_core,snd_hda_codec_hdmi
cx8800 40960 1
cx8802 20480 0
cx88xx 90112 3 cx88_alsa,cx8802,cx8800
videobuf2_dma_sg 16384 1 cx8800
tveeprom 24576 1 cx88xx
v4l2_common 16384 3 tuner,cx88xx,cx8800
videobuf2_v4l2 24576 1 cx8800
videobuf2_core 40960 4 cx8802,cx88xx,videobuf2_v4l2,cx8800
videodev 172032 7 tuner,v4l2_common,cx88_alsa,videobuf2_core,cx88xx,videobuf2_v4l2,cx8800
snd 81920 22 snd_hda_intel,snd_hwdep,snd_seq,snd_hda_codec,cx88_alsa,snd_timer,snd_rawmidi,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_seq_device,snd_hda_codec_realtek,snd_pcm
rc_core 36864 4 rc_winfast,ite_cir,cx88xx
i2c_algo_bit 16384 2 cx88xx,nouveau
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Fix Applied
Ref:
https://unix.stackexchange.com/questions/28240/disable-detection-of-certain-hardware
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Decided to disable driver load.
- $touch /etc/modprobe.d/blacklist-cx88-alsa.conf and edit it.
qyang@Ubuntu1604LTS:~$ cat /etc/modprobe.d/blacklist-cx88_alsa.conf
blacklist cx88_alsa
blacklist cx88xx
blacklist cx8800
blacklist cx8802
- Problem solved after reboot.
