Date: Tue, 02 Dec 2003 19:03:51 +0000 From: Jay Cornwall <jay@evilrealms.net> To: Martin <nakal@web.de> Cc: freebsd-current@freebsd.org Subject: Re: Panic with ugen Message-ID: <3FCCE217.2090302@evilrealms.net> In-Reply-To: <1070218984.675.4.camel@klotz.local> References: <1069874342.704.18.camel@klotz.local> <3FC60935.3050604@evilrealms.net><3FC7510A.8070906@evilrealms.net> <1070218984.675.4.camel@klotz.local>
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Martin wrote:
>>Could you try the attached patch (rm -f sys/dev/usb/ugen.c, cvs up
>>sys/dev/usb/ugen.c, patch ...) to see if it alleviates the panic? It
>>should at least give a more specific panic, if it doesn't fix the problem.
> Sorry for the delay, I got a busy weekend.
And sorry for the delay here too. Had a busy start-of-week. :\
> I still got a panic after starting the small piece of code, but it looks
> like this now:
>
> fatal trap 12
> fault virtual address = 0x5
> supervisor read, page not present
> [...]
>
> trace shows me "ugen_set_config()" at top of the stack.
Hmm. I'm afraid I'm not really sure why my patch doesn't fix the problem.
Unfortunately, to fix this I think I'd need to be able to reproduce the panic
locally and do some debugging. Otherwise, I'd just be guessing at what's
causing the problem.
If you could provide a full backtrace with a debug-enabled kernel
('makeoptions DEBUG=-g' in your kernel configuration file, with GDB using
kernel.debug to obtain symbols - I think onlamp.com had a tutorial on doing
this) I may be able to locate where things are going wrong. But if it's too
much hassle for you, I think it'd be best to pass this on to a developer with
a machine to test the panic on.
Thanks for trying the patches, though. :)
--
Cheers,
Jay
http://www.evilrealms.net/ - Systems Administrator & Developer
http://www.imperial.ac.uk/ - 3rd year CS student
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