> I have an x86 system with two PCI slots, in which I inserted two
> specialized output cards (Dektec DTA-105).
>
>
http://www.dektec.com/Products/DTA-105/
> (They provide an open source driver.)
>
> My problem is: when I write to the 4 ports (each card has 2 ports) "at
> the same time" (not really "at the same time" because I have a
> uni-processor system, so "within a short time frame" is more accurate)
> the system *completely* locks up.
>
> The manufacturer told me they had seen the problem in their lab. I'm
> just trying to provide some helpful debug output to speed up the process
> of fixing the problem :-)
>
> I've built a debug 2.6.22.1-rt9 kernel, hoping to get the kernel to dump
> something, anything.
>
> +CONFIG_KALLSYMS_ALL=y
> +CONFIG_PCI_DEBUG=y
> +CONFIG_DEBUG_DRIVER=y
> +CONFIG_PRINTK_TIME=y
> +CONFIG_MAGIC_SYSRQ=y
> +CONFIG_DEBUG_KERNEL=y
> +CONFIG_DEBUG_SHIRQ=y
> +CONFIG_DETECT_SOFTLOCKUP=y
> +CONFIG_DEBUG_SLAB=y
> +CONFIG_DEBUG_SLAB_LEAK=y
> +CONFIG_DEBUG_PREEMPT=y
> +CONFIG_DEBUG_RT_MUTEXES=y
> +CONFIG_DEBUG_PI_LIST=y
> +CONFIG_RT_MUTEX_TESTER=y
> +CONFIG_DEBUG_SPINLOCK=y
> +CONFIG_DEBUG_MUTEXES=y
> +CONFIG_DEBUG_LOCK_ALLOC=y
> +CONFIG_PROVE_LOCKING=y
> +CONFIG_LOCKDEP=y
> +CONFIG_TRACE_IRQFLAGS=y
> +CONFIG_DEBUG_SPINLOCK_SLEEP=y
> +CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
> +CONFIG_STACKTRACE=y
> +CONFIG_PREEMPT_TRACE=y
> +CONFIG_DEBUG_BUGVERBOSE=y
> +CONFIG_DEBUG_INFO=y
> +CONFIG_FRAME_POINTER=y
> +CONFIG_FORCED_INLINING=y
> +CONFIG_DEBUG_STACKOVERFLOW=y
> +CONFIG_DEBUG_RODATA=y
> +CONFIG_4KSTACKS=y
>
> I've enabled the serial console, and used SysRq to bump the console
> level to 9 (I want everything, even KERN_DEBUG output).
>
> I've enabled the IO-APIC watchdog (nmi_watchdog=1).
>
> Once the system locks up, I get no output, no panic, no oops.
> The serial console is frozen, my ssh sessions are frozen.
>
> Suppose the PCI bus "crashes" (whatever that means) or locks up.
> Would that make the system completely unresponsive? The I/O does have to
> get to/from the south bridge, through the PCI bus AFAIU. I can imagine
> that a locked PCI bus would be slightly problematic.
>
> Does this mean I need some kind of PCI bus analyzer (i.e. hardware) at
> this point? Is there anything more I can try?
