Re: Panic with ugen

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