Comment 0 for bug 1387199

About once per hour, the `wl` kernel module of `bcmwl-kernel-source` crashes. `/var/log/syslog` contains
```
Oct 29 15:10:19 fuji kernel: [73721.579735] 0000000000000009 ffff880262bdbdd0 ffffffff8277fcbc 0000000000000000
Oct 29 15:10:19 fuji kernel: [73721.579738] ffff880262bdbe08 ffffffff8206fd8d ffff880260aa5000 ffff8801367e0840
Oct 29 15:10:19 fuji kernel: [73721.579742] 00000000000000a2 ffff8801facf9d80 ffff880261f28a78 ffff880262bdbe18
Oct 29 15:10:19 fuji kernel: [73721.579745] Call Trace:
Oct 29 15:10:19 fuji kernel: [73721.579755] [<ffffffff8277fcbc>] dump_stack+0x45/0x56
Oct 29 15:10:19 fuji kernel: [73721.579760] [<ffffffff8206fd8d>] warn_slowpath_common+0x7d/0xa0
Oct 29 15:10:19 fuji kernel: [73721.579764] [<ffffffff8206fe6a>] warn_slowpath_null+0x1a/0x20
Oct 29 15:10:19 fuji kernel: [73721.579780] [<ffffffffc030b981>] cfg80211_roamed+0x91/0xa0 [cfg80211]
Oct 29 15:10:19 fuji kernel: [73721.579828] [<ffffffffc06958cb>] wl_notify_roaming_status+0xcb/0x150 [wl]
Oct 29 15:10:19 fuji kernel: [73721.579870] [<ffffffffc0692602>] wl_event_handler+0x62/0x260 [wl]
Oct 29 15:10:19 fuji kernel: [73721.579911] [<ffffffffc06925a0>] ? wl_free_wdev.isra.23+0x80/0x80 [wl]
Oct 29 15:10:19 fuji kernel: [73721.579915] [<ffffffff82094aeb>] kthread+0xdb/0x100
Oct 29 15:10:19 fuji kernel: [73721.579920] [<ffffffff82094a10>] ? kthread_create_on_node+0x1c0/0x1c0
Oct 29 15:10:19 fuji kernel: [73721.579924] [<ffffffff82787c3c>] ret_from_fork+0x7c/0xb0
Oct 29 15:10:19 fuji kernel: [73721.579928] [<ffffffff82094a10>] ? kthread_create_on_node+0x1c0/0x1c0
Oct 29 15:10:19 fuji kernel: [73721.579930] ---[ end trace f2631d4af0f9ba2d ]---
```

Further system info:
```
$ lspci -vvnn | grep -A 11 Network
03:00.0 Network controller [0280]: Broadcom Corporation BCM4331 802.11a/b/g/n [14e4:4331] (rev 02)
 Subsystem: Apple Inc. AirPort Extreme [106b:00d6]
 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0, Cache Line Size: 256 bytes
 Interrupt: pin A routed to IRQ 17
 Region 0: Memory at a0600000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: <access denied>
 Kernel driver in use: wl

04:00.0 FireWire (IEEE 1394) [0c00]: LSI Corporation FW643 [TrueFire] PCIe 1394b Controller [11c1:5901] (rev 08) (prog-if 10 [OHCI])
 Subsystem: LSI Corporation FW643 [TrueFire] PCIe 1394b Controller [11c1:5900]
```
```
$ lsb_release -rd
Description: Ubuntu 14.10
Release: 14.10
```
```
$ uname -a
Linux fuji 3.16.0-23-generic #31-Ubuntu SMP Tue Oct 21 17:56:17 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
```
```
$ apt-cache policy bcmwl-kernel-source
bcmwl-kernel-source:
  Installed: 6.30.223.248+bdcom-0ubuntu1
  Candidate: 6.30.223.248+bdcom-0ubuntu1
  Package pin: (not found)
  Version table:
 *** 6.30.223.248+bdcom-0ubuntu1 1001
        500 http://ubuntu.mirror.tudos.de/ubuntu/ utopic/restricted amd64 Packages
        100 /var/lib/dpkg/status
```
```
$ sudo dmidecode -s bios-version
   MBP81.88Z.0047.B27.1201241646
```
```
$ sudo dmidecode -s bios-release-date
01/24/12
```
```
$ sudo dmidecode -s baseboard-product-name
Mac-94245B3640C91C81
```
```
$ sudo dmidecode -s baseboard-manufacturer
Apple Inc.
```