reset with fwcontrol -R

[Kazumaro Aoki]

Hello, members of freebsd-firewire!

From: Kazumaro Aoki <ka at flu.if0.org>
Subject: Re: reset with fwcontrol -R
Date: Sun, 07 Feb 2010 22:09:56 +0900 (JST)

> In recent month, the system is in good condition, but today morning,
> system crashed and made a crash dump.
(snip)
> # kgdb /boot/kernel/kernel vmcore.1
(snip)
> Fatal trap 12: page fault while in kernel mode
> current process         = 42 (fw0_taskq)
> panic: page fault
(snip)
> (kgdb) bt
(snip)
> #7  0xc05f6d87 in fwohci_task_dma (arg=0xc5662000, pending=1)
>     at /home/usr/src/sys/dev/firewire/fwohci.c:2206
(snip)

I met the similar panic twice, after I saw the above message.
First, the crash dump was unfortunately not made.
Second, the crash dump was made and kgdb said the same line
(FreeBSD7.2R) causes the panic.

Now, I configured the kernel and I used the loadable module of
firewire.  So, I can easy to modify the module and it enables to add
to show debug information other than "sysctl debug.firewire_debug=3".

I noticed lines 2197-2199 are
#if 0
	dump_db(sc, dmach);
#endif
Are the information generated by the commented out the lines useful to
analyze the problem?

I feel that to start fwcontrol -R when finishing fwcontrol -R just
after typing ctrl-c may cause a panic.  I will confirm this tomorrow.

Best regards,

Kazumaro