Most recent kernel where this bug did not occur: unknown Hardware Environment: SMP i586 and SMP x86-64 Software Environment: Linux 2.6.x If an SBP-2 device is attached and sbp2 or firewire-sbp2 is loaded, any of the following commands # modprobe -r sbp2 && modprobe -r ohci1394 # modprobe -r firewire-ohci # modprobe -r firewire-sbp2 firewire-ohci # modprobe -r firewire-sbp2 && sleep 0 && modprobe -r firewire-ohci will lead to a panic with a trace similar to this: general protection fault [...] Pid: 0, comm: swapper [...] run_timer_softirq __do_softirq call_softirq do_softirq irq_exit smp_apic_timer_interrupt mwait_idle apic_timer_interrupt [...] This happened on two different i945GM based boards with Core 2 Duo, 32-bit and 64-bit kernels. The last time I tried this with ohci1394/sbp2 is a while ago. I just saw it now happening in the new drivers too. The same trace also happened on an older kernel repeatedly in a totally different context, without FireWire drivers loaded: It could be triggered by "make -j" in the kernel source tree, i.e. by a spawning something with many subthreads. I don't have a spare machine with enough RAM available to test this again with a recent kernel, for now. I will try to make the machine where I saw it available again. I.e. the bug may be entirely outside the old and new FireWire drivers. *Not* affected are: - The same machines with "modprobe -r firewire-sbp2 && sleep 0.1 && modprobe -r firewire-ohci", - A VIA KM-266/ AMD-Athlon single-CPU PC, even if running an SMP kernel. I will attach a sample screenshot in a follow-up entry.
Created attachment 11773 [details] screenshot
An old Pentium MMX notebook also crashes this way but does not print out a panic message. Tested with UP PREEMPT kernel.
Created attachment 12445 [details] screenshot panic on 2.6.23-rc3 x86-64 triggered by modprobe -r firewire-ohci shortly after modprobe firewire-ohci, firewire-sbp2 was not loaded
Created attachment 12461 [details] kill tasklets in fw-ohci::pci_remove It seems this patch doesn't help. See next screenshot.
Created attachment 12462 [details] screenshot panic, with patch id=12461 applied, triggered by modprobe -r firewire-ohci with an SBP-2 disk attached and firewire-sbp2 loaded The only and probably insignificant difference is that __update_rq_clock (a new function in 2.6.23-rc3) appears in the trace between __do_softirq and run_timer_softirq.
Created attachment 12463 [details] firewire: fix unloading of fw-ohci while devices are attached Fixes modprobe -r firewire-ohci in presence of an SBP-2 device.
Still to do: - Check if patch attachment 12469 [details] also fixed the bug per comment #3. We can't tell for sure as long as bug 8906 is unfixed. - Fix the bug for the old ieee1394 stack.
(I meant attachment 12463 [details] of course.)
attachment 12463 [details] has been merged in linux 2.6.23-rc4
Re comment #7: Fixes for bug 8906 have been posted, bug per comment #3 does not happen anymore. I.e. only the old ieee1394 stack _may_ still be affected. I am closing this bug now; if anybody still encounters this bug with the ieee1394 stack, please reopen and rename this bug.