Comment 17 for bug 2043905

Hi Beyil,

> I do have an old system (Phenom 1090T CPU) on a motherboard that has a
> 1394a controller built in that the 6.5.0-10 kernel works properly on...

Indeed. I also own AMD 880G chipset machine with AMD Sempron 145 CPU. It
works well even if using the issued version of kernel. Furthermore, VIA
VT6307 card without ASM1083 also works well in the machine.

> would some sort of system report from that machine help in tracking down
> the issue? or even a report from the system with the issue with an
> earlier kernel (6.2.0-36) with the card installed?? I know the phenom
> is a pre-ryzen so it may be totally missing a CPU command structure that
> is possibly effected, and the Lunar kernel which isn't effected may also
> be missing something even though the rest of the system is with the up
> to date 23.10 build.. would be interesting if somehow could run a 6.5
kernel under the 6.2 kernel to get a log of some sort.

Thanks for your suggestion, while the problem occurs due to operations
which is not so special, at least, it is not unique instructions supported
by AMD Ryzen CPU. The cause is to access to registers by the way of
standard PCI express way in some situations.

> I have VirtualBox installed but that provides its own "box" and doesn't
> really use the current hardware...

In the case that we utilize PCI passthrough to bind the issued 1394 OHCI
card to guest system, I note that the guest system can bring the system
reboot to host system, if the guest system run with v6.5 kernel or later.

> also my motherboard has 2 PCIe slots, one connected directly to the
> CPU and another connected through the B550 chipset the reboot loop
> happens regardless of which slot is used. I mainly use the one through
> the B550 chipset to not restrict airflow into the GPU.

Indeed. I also experienced that changing PCIe slot is helpless to solve
the issue.