[natty] Broadcom STA Driver: divide error: 0000

[Edmundo]

Hi!

I've been using the bcmwl driver since Maverick on this laptop without much problem, however on Natty I hadn't been using it much (I updated to natty a few days before the final release and I keep it updated). Today I started using it to connect to internet and I'm noticing that after a while one ksoftirqd process starts taking 100% CPU time and I will lose wireless connection and so on... in a few words, I have to reboot it (wait for the computer to _not_ finish rebooting and I will send alt-sysrq key combinations to reboot it after a while).

I went into dmesg after one of this process hang events and this is what I found:

[ 1757.127398] divide error: 0000 [#1] SMP
[ 1757.127534] last sysfs file: /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map
[ 1757.127757] Modules linked in: cryptd aes_i586 aes_generic nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables rfcomm sco bnep l2cap parport_pc ppdev dm_crypt wl(P) lib80211 arc4 snd_hda_codec_realtek snd_hda_intel snd_hda_codec joydev snd_hwdep snd_pcm btusb snd_seq_midi bluetooth uvcvideo snd_rawmidi snd_seq_midi_event psmouse snd_seq videodev brcm80211(C) mac80211 serio_raw snd_timer snd_seq_device snd cfg80211 soundcore snd_page_alloc lp parport i915 ahci drm_kms_helper drm libahci sky2 i2c_algo_bit video
[ 1757.129388]
[ 1757.129439] Pid: 0, comm: swapper Tainted: P C 2.6.38-8-generic #42-Ubuntu SAMSUNG ELECTRONICS CO., LTD. N150P/N210P/N220P /N150P/N210P/N220P
[ 1757.131284] EIP: 0060:[<f862c0fe>] EFLAGS: 00010246 CPU: 0
[ 1757.131284] EIP is at minstrel_ht_update_stats.clone.5+0x1fe/0x430 [mac80211]
[ 1757.145583] EAX: 0000006c EBX: 0000006c ECX: eec10050 EDX: 00000000
[ 1757.145583] ESI: 00000000 EDI: eec10068 EBP: f3c0bed4 ESP: f3c0be90
[ 1757.145583] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1757.145583] Process swapper (pid: 0, ti=f3c0a000 task=c1731f60 task.ti=c172c000)
[ 1757.145583] Stack:
[ 1757.145583] 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 1757.145583] 00004858 00000000 eec10000 eec10000 00000000 00000001 f075c800 eec10000
[ 1757.145583] 00000003 f3c0bf10 f862c744 00000001 f3c0bf20 00000000 00000001 ed980228
[ 1757.145583] Call Trace:
[ 1757.145583] [<f862c744>] minstrel_ht_tx_status+0x414/0x4a0 [mac80211]
[ 1757.145583] [<f8603538>] ieee80211_tx_status+0x1c8/0x880 [mac80211]
[ 1757.145583] [<f8b4df6a>] ? wlc_bmac_txstatus+0xba/0x1a0 [brcm80211]
[ 1757.145583] [<f8b11faa>] ? wlc_ps_check+0x2a/0x160 [brcm80211]
[ 1757.145583] [<c14258a0>] ? skb_dequeue+0x50/0x70
[ 1757.145583] [<f8602aa7>] ieee80211_tasklet_handler+0x97/0xc0 [mac80211]
[ 1757.145583] [<c1509716>] ? _raw_spin_unlock_bh+0x16/0x20
[ 1757.145583] [<f8b1f8a8>] ? wl_dpc+0x58/0xb0 [brcm80211]
[ 1757.145583] [<c1055ee5>] tasklet_action+0x55/0xe0
[ 1757.145583] [<c1056622>] __do_softirq+0x82/0x170
[ 1757.145583] [<c10565a0>] ? __do_softirq+0x0/0x170
[ 1757.145583] <IRQ>
[ 1757.145583] [<c10567ed>] ? irq_exit+0x6d/0x80
[ 1757.145583] [<c15107ab>] ? do_IRQ+0x4b/0xc0
[ 1757.145583] [<c107cbca>] ? tick_notify+0x11a/0x1d0
[ 1757.145583] [<c1003670>] ? common_interrupt+0x30/0x38
[ 1757.145583] [<c105007b>] ? console_unlock+0xdb/0xe0
[ 1757.145583] [<c12c2508>] ? intel_idle+0xb8/0x110
[ 1757.145583] [<c14061fd>] ? cpuidle_idle_call+0x7d/0x160
[ 1757.145583] [<c10019ca>] ? cpu_idle+0x8a/0xc0
[ 1757.145583] [<c1038d2e>] ? complete+0x4e/0x60
[ 1757.145583] [<c14f0d2d>] ? rest_init+0x5d/0x70
[ 1757.145583] [<c178d7e1>] ? start_kernel+0x35f/0x366
[ 1757.145583] [<c178d3d5>] ? pass_all_bootoptions+0x0/0xa
[ 1757.145583] [<c178d0e0>] ? i386_start_kernel+0xe0/0xe8
[ 1757.145583] Code: 51 04 89 41 fc 8b 5f 08 81 fb 98 19 00 00 89 5d dc 0f 86 16 ff ff ff 8b 55 e4 8b 45 e4 8b 5a 1c 31 d2 0f b7 40 0a 89 45 d4 89 d8 <f7> 75 d4 8b 55 d8 89 c3 b8 40 42 0f 00 03 9c b2 a8 fd 62 f8 31
[ 1757.145583] EIP: [<f862c0fe>] minstrel_ht_update_stats.clone.5+0x1fe/0x430 [mac80211] SS:ESP 0068:f3c0be90
[ 1757.145583] BUG: scheduling while atomic: swapper/0/0x10000100
[ 1757.145583] Modules linked in: cryptd aes_i586 aes_generic nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables rfcomm sco bnep l2cap parport_pc ppdev dm_crypt wl(P) lib80211 arc4 snd_hda_codec_realtek snd_hda_intel snd_hda_codec joydev snd_hwdep snd_pcm btusb snd_seq_midi bluetooth uvcvideo snd_rawmidi snd_seq_midi_event psmouse snd_seq videodev brcm80211(C) mac80211 serio_raw snd_timer snd_seq_device snd cfg80211 soundcore snd_page_alloc lp parport i915 ahci drm_kms_helper drm libahci sky2 i2c_algo_bit video
[ 1757.145583] Modules linked in: cryptd aes_i586 aes_generic nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables rfcomm sco bnep l2cap parport_pc ppdev dm_crypt wl(P) lib80211 arc4 snd_hda_codec_realtek snd_hda_intel snd_hda_codec joydev snd_hwdep snd_pcm btusb snd_seq_midi bluetooth uvcvideo snd_rawmidi snd_seq_midi_event psmouse snd_seq videodev brcm80211(C) mac80211 serio_raw snd_timer snd_seq_device snd cfg80211 soundcore snd_page_alloc lp parport i915 ahci drm_kms_helper drm libahci sky2 i2c_algo_bit video
[ 1757.145583]
[ 1757.145583] Pid: 0, comm: swapper Tainted: P C 2.6.38-8-generic #42-Ubuntu SAMSUNG ELECTRONICS CO., LTD. N150P/N210P/N220P /N150P/N210P/N220P
[ 1757.145583] EIP: 0060:[<c12c2508>] EFLAGS: 00000246 CPU: 0
[ 1757.145583] EIP is at intel_idle+0xb8/0x110
[ 1757.145583] EAX: 00000000 EBX: 00000000 ECX: 0000028d EDX: 00000000
[ 1757.145583] ESI: 12226bb7 EDI: 00000004 EBP: c172df60 ESP: c172df48
[ 1757.145583] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1757.145583] Process swapper (pid: 0, ti=f3c0a000 task=c1731f60 task.ti=c172c000)
[ 1757.145583] Stack:
[ 1757.145583] 0000028d 00000000 00000000 c1788e4c f700ab5c 36e97000 c172df80 c14061fd
[ 1757.145583] f700ac1c 00000000 00000002 c1788e4c 00000000 36e97000 c172dfa0 c10019ca
[ 1757.145583] c1038d2e 00000000 42a3b622 1d66713b c17cda60 34716712 c172dfa8 c14f0d2d
[ 1757.145583] Call Trace:
[ 1757.145583] [<c14061fd>] cpuidle_idle_call+0x7d/0x160
[ 1757.145583] [<c10019ca>] cpu_idle+0x8a/0xc0
[ 1757.145583] [<c1038d2e>] ? complete+0x4e/0x60
[ 1757.145583] [<c14f0d2d>] rest_init+0x5d/0x70
[ 1757.145583] [<c178d7e1>] start_kernel+0x35f/0x366
[ 1757.145583] [<c178d3d5>] ? pass_all_bootoptions+0x0/0xa
[ 1757.145583] [<c178d0e0>] i386_start_kernel+0xe0/0xe8
[ 1757.145583] Code: c9 e8 3d 5a db ff 29 d8 bb 40 42 0f 00 19 f2 e8 9f 28 d9 ff 89 d1 f7 eb 89 cb c1 fb 1f 89 45 e8 01 4d e8 89 55 ec 11 5d ec fb 90 <8d> 74 26 00 85 3d 20 15 76 c1 75 0d 8d 55 f0 b8 05 00 00 00 e8
[ 1757.145583] Call Trace:
[ 1757.145583] [<c14061fd>] cpuidle_idle_call+0x7d/0x160
[ 1757.145583] [<c10019ca>] cpu_idle+0x8a/0xc0
[ 1757.145583] [<c1038d2e>] ? complete+0x4e/0x60
[ 1757.145583] [<c14f0d2d>] rest_init+0x5d/0x70
[ 1757.145583] [<c178d7e1>] start_kernel+0x35f/0x366
[ 1757.145583] [<c178d3d5>] ? pass_all_bootoptions+0x0/0xa
[ 1757.145583] [<c178d0e0>] i386_start_kernel+0xe0/0xe8
[ 1758.489595] Associated: False
[ 1758.572228] cfg80211: All devices are disconnected, going to restore regulatory settings
[ 1758.577251] cfg80211: Restoring regulatory settings
[ 1758.585943] cfg80211: Calling CRDA to update world regulatory domain
[ 1758.608158] cfg80211: Updating information on frequency 2412 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.611987] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.616038] cfg80211: Updating information on frequency 2417 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.619990] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.623921] cfg80211: Updating information on frequency 2422 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.628035] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.632071] cfg80211: Updating information on frequency 2427 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.636307] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.640609] cfg80211: Updating information on frequency 2432 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.644991] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.649290] cfg80211: Updating information on frequency 2437 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.653842] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.658249] cfg80211: Updating information on frequency 2442 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.662969] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.667656] cfg80211: Updating information on frequency 2447 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.672463] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.677273] cfg80211: Updating information on frequency 2452 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.681987] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.686801] cfg80211: Updating information on frequency 2457 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.692051] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.697296] cfg80211: Updating information on frequency 2462 MHz for a 20 MHz width channel with regulatory rule:
[ 1758.702766] cfg80211: 2402000 KHz - 2472000 KHz @ KHz), (300 mBi, 2700 mBm)
[ 1758.708464] cfg80211: Disabling freq 2467 MHz
[ 1758.713873] cfg80211: Disabling freq 2472 MHz
[ 1758.719067] cfg80211: Disabling freq 2484 MHz
[ 1758.724290] cfg80211: World regulatory domain updated:
[ 1758.729389] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[ 1758.734602] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 1758.739825] cfg80211: (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 1758.745119] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 1758.750174] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 1758.755417] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)

Sounds like a bug on the driver, doesn't it?

A top from the moment when I noticed the bug had gone off a few seconds later:
top - 22:18:12 up 32 min, 4 users, load average: 1.06, 0.59, 0.36
Tasks: 155 total, 2 running, 153 sleeping, 0 stopped, 0 zombie
Cpu(s): 10.1%us, 54.3%sy, 0.0%ni, 35.6%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 2050004k total, 1185792k used, 864212k free, 78356k buffers
Swap: 3952636k total, 0k used, 3952636k free, 662680k cached

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
    3 root 20 0 0 0 0 R 100 0.0 3:42.70 ksoftirqd/0
  915 root 20 0 51128 16m 5252 S 12 0.8 3:44.20 Xorg
 1701 antoranz 20 0 129m 23m 16m S 8 1.2 0:15.13 konsole
 1570 antoranz 20 0 383m 86m 37m S 3 4.3 2:09.93 plasma-desktop
 1532 antoranz 20 0 296m 25m 16m S 2 1.3 0:36.78 knotify4
 1525 antoranz 20 0 194m 36m 26m S 1 1.8 0:14.52 kwin
 1988 antoranz 20 0 40588 10m 8824 S 1 0.5 0:14.83 gkrellm
 2684 antoranz 20 0 260m 62m 32m S 1 3.1 0:35.03 ktorrent
 3410 antoranz 20 0 2632 1156 860 R 1 0.1 0:01.54 top
etc

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: bcmwl-kernel-source 5.100.82.38+bdcom-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
NonfreeKernelModules: wl
Architecture: i386
Date: Sun May 29 22:28:37 2011
InstallationMedia: Kubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 LANGUAGE=
 LANG=es_CO.UTF-8
 SHELL=/bin/bash
SourcePackage: bcmwl
UpgradeStatus: No upgrade log present (probably fresh install)

[nutznboltz (nutznboltz-deactivatedaccount)]

If you pay less attention to:
[ 1757.127398] divide error: 0000 [#1] SMP

And focus on:
[ 1757.145583] BUG: scheduling while atomic: swapper/0/0x10000100

You will find others with this issue too.

BUG: scheduling while atomic 2.6.39-rc7 (iwl3945_irq_tasklet)
http://lkml.org/lkml/2011/5/13/393

That bug report is also "scheduling while atomic" (during softirq) but with iwl3945 wifi driver instead of scsi. Was abandoned because too hard to reproduce.

Re: rtlwifi: regression 39-rc5 (rtl8192ce)
https://lkml.org/lkml/2011/5/2/135

Again "scheduling while atomic" and abandoned because too hard to reproduce.

Only not iwl3945 wifi but rtl8192ce wifi.

For you bcmwl. Also LP: #793796 is "scheduling while atomic" (during softirq) but not wifi at all.