kern/189802: amd64 current 264294 panic: breakpoint instruction fault, possibly iwn bug

[Anton Shterenlikht]

>Number:         189802
>Category:       kern
>Synopsis:       amd64 current 264294 panic: breakpoint instruction fault, possibly iwn bug
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed May 14 13:50:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     Anton Shterenlikht
>Release:        FreeBSD 11.0-CURRENT ia64
>Organization:
>Environment:
System: FreeBSD 11.0-CURRENT #11 r264294: Wed Apr  9 13:38:12 BST 2014
    root at mech-aslap33.men.bris.ac.uk:/usr/obj/usr/src/sys/MINKY amd64

	
>Description:

I'm seeing spontaneous reboots on an amd64 laptop with iwn
card. I haven't enabled a dump partition yet (will try to do),
so all I get is:

Fatal trap 3: breakpoint instruction fault while in kernel mode
cpuid = 0; apic id = 00
instruction pointer     = 0x20:0xffffffff805b173e
stack pointer           = 0x28:0xffffffff81018590
frame pointer           = 0x28:0xffffffff810185b0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = IOPL = 0
current process         = 12 (irq259: iwn0)
trap number             = 3
panic: breakpoint instruction fault
cpuid = 0
KDB: enter: panic

iwn behaves really badly, and disconnects every few minutes
with:

wlan0: Ethernet address: 00:21:5c:50:68:c3
wlan0: link state changed to UP
iwn0: iwn_intr: fatal firmware error
firmware error log:
  error type      = "FH_ERROR" (0x0000000C)
  program counter = 0x0000046C
  source line     = 0x000000D0
  error data      = 0x0000000802730000
  branch link     = 0x0000A332000004C2
  interrupt link  = 0x000006DE0000A37E
  time            = 2607530651
driver status:
  tx ring  0: qid=0  cur=22  queued=12
  tx ring  1: qid=1  cur=0   queued=0
  tx ring  2: qid=2  cur=0   queued=0
  tx ring  3: qid=3  cur=16  queued=0
  tx ring  4: qid=4  cur=81  queued=0
  tx ring  5: qid=5  cur=0   queued=0
  tx ring  6: qid=6  cur=0   queued=0
  tx ring  7: qid=7  cur=0   queued=0
  tx ring  8: qid=8  cur=0   queued=0
  tx ring  9: qid=9  cur=0   queued=0
  tx ring 10: qid=10 cur=0   queued=0
  tx ring 11: qid=11 cur=0   queued=0
  tx ring 12: qid=12 cur=0   queued=0
  tx ring 13: qid=13 cur=0   queued=0
  tx ring 14: qid=14 cur=0   queued=0
  tx ring 15: qid=15 cur=0   queued=0
  rx ring: cur=39
ifa_del_loopback_route: deletion failed: 3
wlan0: link state changed to DOWN
wlan0: Ethernet address: 00:21:5c:50:68:c3
wlan0: link state changed to UP

This is a known problem:
http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/176104

It is interesting to note that iwn
disconnects a lot at work, and very rarely
at home. I suspect that it is too sensitive
to interference, or something like this.

Anyway, I'll try to provide textdump
if I set it up.

	
>How-To-Repeat:
	
>Fix:

	


>Release-Note:
>Audit-Trail:
>Unformatted: