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

[Andriy Gapon]

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").

-- 
Andriy Gapon