Re: [Line6linux-user] line6linux problem with pod xt live

[Markus G. <gr...@ic...>]

Am Donnerstag, 10. Januar 2013, 21:51:56 schrieb Mariusz Kozlowski:
> On Thu, Jan 10, 2013 at 09:24:54PM +0100, Markus Grabner wrote:
> > Am Dienstag, 8. Januar 2013, 23:54:20 schrieben Sie:
> > > BTW. I think I found another bug ... this is minor but probably should
> > > get fixed. If you rmmod before driver finishes initialisation it
> > > is likely to get oops.
> > > 
> > > Try something like this:
> > > 
> > > # while true; do insmod line6usb.ko; sleep 0.1; rmmod line6usb; sleep 1;
> > > done
> > 
> > I let this run for ~30 minutes and did normal work during this time, but
> > was not able to reproduce the crash. Our machines seem to have somewhat
> > different timings...
> > 
> > Nevertheless, termination of the startup procedure could be done more
> > carefully, which I checked in as r987. Another problem might be the sysfs
> > files, which are removed before the startup procedure is terminated, i.e.,
> > in rare occasions those files could be created after the attempt to
> > delete them. Since the sysfs files will be removed from the driver in the
> > future, I don't want to spend too much time on them right now. You could
> > try to move the timer and workqueue related lines in
> > [pod|variax]_destruct into the corresponding *_disconnect function
> > (before the device_remove_file lines) to see if it makes a difference
> > (though I don't think so).
> 
> I'll try to dig a bit deeper on my own. That sounds like a good
> exercise. This isn't a big issue anyway but just could get fixed.
A kernel debugger (http://www.kernel.org/doc/htmldocs/kgdb.html) might be 
helpful. In case of a crash, the processor enters a simple terminal which 
allows you to get a stack dump, examine memory content etc. You should work on 
a text console since the kernel debugger won't switch to text mode if the 
machine was in graphics mode (X11) during the crash. Alternatively, you could 
use a serial port for kernel debugging, but I never tried this. Good luck!

	Kind regards,
		Markus