Comment 3 for bug 1279403

I enabled kgdboc=ttyS0,115200 and caught this :

[ 71.145241] input: Barcode Reader as /devices/ffe000000.soc/ffe210000.usb/fsl-ehci.0/usb1/1-1/1-1.3/1-1.3:1.1/input/input1
[ 71.145493] hid-generic 0003:13BA:0018.0002: input,hidraw1: USB HID v1.10 Mouse [Barcode Reader ] on usb-fsl-ehci.0-1.3/input1
[ 71.206233] md: raid6 personality registered for level 6
[ 71.206235] md: raid5 personality registered for level 5
[ 71.206236] md: raid4 personality registered for level 4
[ 71.260531] md: raid10 personality registered for level 10
[ 71.664609] udlfb: DisplayLink USB device /dev/fb0 attached. 1440x900 resolution. Using 5064K framebuffer memory
[ 71.934176] IPv6: ADDRCONF(NETDEV_UP): eth2: link is not ready
[ 72.083988] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready
[ 73.549288] tg3 0000:01:00.0 eth2: Link is up at 100 Mbps, full duplex

Entering kdb (current=0xe62b8000, pid 74) on processor 1 Oops: (null)
due to oops @ 0x0
dCPU: 1 PID: 74 Comm: kworker/1:1 Tainted: G W 3.13.9+ #3
dWorkqueue: events linkwatch_event
dtask: e62b8000 ti: e6396000 task.ti: e6396000
NIP: 00000000 LR: c00885ac CTR: 00000000
REGS: e6397ca0 TRAP: 0400 Tainted: G W (3.13.9+)
MSR: 00021002 <CE,ME> CR: 22ad2e28 XER: 00000000

GPR00: c00885ac e6397d50 e62b8000 d1826900 c0b0b340 00000005 448130bc 00000011
GPR08: 00000000 00000000 00000011 204c2f00 00000000 00000000 c0078250 e62c7920
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 d1826680
GPR24: c0b60000 10d20000 c0b06900 c0b06900 c0b80e18 e6396000 d1826900 c0b0b340
NIP [00000000] (null)
LR [c00885ac] ttwu_do_activate.constprop.70+0x4c/0x90
Call Trace:
[e6397d50] [c00885ac] ttwu_do_activate.constprop.70+0x4c/0x90 (unreliable)
[e6397d60] [c0089d80] scheduler_ipi+0xb0/0x1e0
[e6397d90] [c00126d0] smp_ipi_demux+0xa0/0xf0
[e6397db0] [c0010250] doorbell_exception+0x70/0xa0
[e6397dd0] [c0010bb0] ret_from_except_full+0x0/0x4c
--- Exception: 2070 at linkwatch_event+0x0/0x50
    LR = process_one_work+0x14c/0x3e0
[e6397e90] [c006fef8] process_one_work+0x128/0x3e0 (unreliable)
[e6397ec0] [c00708d4] worker_thread+0x134/0x3e0
[e6397ef0] [c0078324] kthread+0xd4/0xf0
[e6397f40] [c001068c] ret_from_kernel_thread+0x5c/0x64