[LAU] Bug: kernel or ardour related?

[Steve Fosdick]

On 15/12/2008 23:23:44, Matthias Schönborn reported his system hanging 
for a few seconds, an ACPI related message and a subsequent segfault 
from running ardour with fglrx-modules on a rt kernel.

In general, any complete hang indicates a bug in the kernel, one of the 
modules the kernel has loaded or data the kernel has imported (for 
example, ACPI tables).

This is because an application, such as ardour, only runs when the 
kernel permits it to run and only has access to the memory the kernel 
has granted it access to.  Sometimes a badly behaving application can 
expose a bug in the kernel that well-behaved applications do not and 
maybe the bad behaviour is a result of a bug in the application but the 
kernel bug is still there.

In your case there are three things that all live inside the kernel 
memory that are potential suspects:

1. The fglrx modules.
2. The -rt patch
3. Your BIOS's APCI tables.

It is possible, though harder, to change the APCI tables so I would 
start with the other two, i.e. try running ardour with:

A non-rt kernel but with the fglrx modules.

A rt kernel with whatever graphics card driver you can make work with 
your hardware that is part of the kernel rather than the fglrx modules, 
even if this is VGA or VESA mode.  Even if it not very usable like that 
it will still prove the point.

This may isolate one of the two as being at fault.  If it works fine in 
both of those two combinations above but not when fglrx and rt are 
installed together then maybe the writers of fglrx made assumptions 
that don't hold true with rt, i.e. they are not compatible.

If both of the above combinations show the same hang problem then maybe 
it is time to look at the ACPI tables.

Regards,
Steve.