dev/isp panic (was Re: CAM Target Layer and dev/isp)

[Trent Nelson]

On 7/19/12 1:55 AM, "Andriy Gapon" <avg at FreeBSD.org> wrote:

>on 18/07/2012 17:00 Matthew Jacob said the following:
>> --------------
>> 
>> db> bt
>> Tracing pid 12 tid 100062 td 0xfffffe001c00f470
>> acpi_timer_get_timecount() at 0xffffffff803ccfc6 =
>> acpi_timer_get_timecount+0x16
>> DELAY() at 0xffffffff80ce68c3 = DELAY+0x83
>> ns8250_putc() at 0xffffffff807a17ba = ns8250_putc+0x9a
>> uart_cnputc() at 0xffffffff807a3b85 = uart_cnputc+0x75
>> cnputc() at 0xffffffff808e9cbc = cnputc+0x4c
>> cnputs() at 0xffffffff808ea0f5 = cnputs+0x35
>> putbuf() at 0xffffffff8097400c = putbuf+0xac
>> kvprintf() at 0xffffffff80972643 = kvprintf+0x83
>> vprintf() at 0xffffffff80973b15 = vprintf+0x85
>> printf() at 0xffffffff80973be7 = printf+0x67
>> isp_prt() at 0xffffffff805c15a0 = isp_prt+0xd0
>> isp_async() at 0xffffffff805c6736 = isp_async+0x356
>> isp_intr() at 0xffffffff805b854c = isp_intr+0x13ac
>> isp_platform_intr() at 0xffffffff805c1fd9 = isp_platform_intr+0x99
>> intr_event_execute_handlers() at 0xffffffff80907214 =
>> intr_event_execute_handlers+0x104
>> ithread_loop() at 0xffffffff809089a6 = ithread_loop+0xa6
>> fork_exit() at 0xffffffff809038ef = fork_exit+0x11f
>> fork_trampoline() at 0xffffffff80c5139e = fork_trampoline+0xe
>> --- trap 0, rip = 0, rsp = 0xffffff9178bd3cf0, rbp = 0 ---
>> db> x/s panicstr
>> 0xffffffff8130fd08 = panicstr:
>> 
>> 
>> -------------
>> 
>> Hmm. No panic string because it wasn't a panic. isp driver is trying to
>> (successfully) print something and this blew up in the ACPI code. If
>>there was a
>> bad string it would have blown up in kvprintf.  At least that's my read
>>of this.
>
>I think that the vague reference to ACPI is unnecessarily too vague,
>given the
>quite obvious stack trace (hint: DELAY) and both simplicity and utility of
>acpi_timer_get_timecount (essentially an I/O read operation).
>But there is no indication in the above stack trace that something blew
>up at
>all (no magic words like "panic", "trap").

Hrm.  What else would cause 'db>' to show up on the console?  Ctrl-Alt-Esc
and hitting a breakpoint are all I can think of at the moment -- and
neither of those are applicable here.


	Trent.