Re: Possible regression with the FW643 chipset

Hi Jonathan,

Good you reported it even before I did.

I have 3 different systems with FW643 and the problem persists across all of them. I also have some old thinkpad with TI chipset express-card. No any discoverable issue there. So I am quite certain its chipset specific here.

Here is another report of same problematic chipset and user not aware that he also used the same one in several tests:
<https://github.com/takaswie/linux-firewire-dkms/issues/59>

Thank you for your interest,

I am willing to build kernels and test patches.

On June 19, 2025 11:22:42 PM UTC, Jonathan Woithe <[email protected]> wrote:
>Hi all
>
>The FFADO project has received several reports from people running recent
>kernels which suggest the kernel has stopped detecting bus resets when a
>PCIe FW643 host controller is in use, and (perhaps as a result) is failing
>to enumerate devices on the bus.  This was first reported by a user running
>Fedora 42.  When running Fedora 41 their system would detect firewire
>devices without any issues, and /dev/fw1 was created.  When they upgraded to
>Fedora 42, however, /dev/fw1 wasn't being created and the system logs didn't
>contain any messages from the firefire subsystem to indicate that any
>devices had been seen.
>
>Another user running Endeavour OS also reported the same trouble.
>
>The failure to detect devices applied when devices were connected at boot
>and if they were plugged in sometime after booting.
>
>Follow up discussions suggest that kernel 6.6 is okay while 6.12 and all
>versions which follow it are not.  The problem only seems to affect users
>with FW643 host controllers.  The precise kernel version that first
>displayed the symptoms is not yet identified.
>
>For those affected by this issue and running kernel 6.14.5, the following
>command sequence usually results in a correctly functioning firewire system:
>
>    sudo modprobe -r firewire-ohci
>    sudo modprobe -r firewire-core
>    sleep 2
>    sudo modprobe firewire-ohci
>
>It has been reported that this does not work in 6.14.3 or 5.14.4.
>
>Since the reporters are not developers, the kernels they have access to are
>limited to those supported out of the box by their distributions.  A git
>bisect will only be possible if someone with the requisite knowledge can
>also reproduce the problem.  The information to hand at present is therefore
>somewhat incomplete.  It may take some time to obtain a clear picture of
>what might be going on.
>
>Unfortunately I don't personally have a FW643 host controller so I am not
>able to investigate this myself.  For what it's worth, the 6.12.26 kernel is
>fine for me when using a TI PCI host controller.
>
>At this stage I was wondering whether there have been any changes between
>the 6.6 and 6.12 kernels within the firewire subsystem (or maybe the PCIe
>subsystem) which could have inadvertently caused this issue with FW643 host
>controllers.
>
>Alternatively, are there any FW643 users who have no problem with device
>detection under a 6.12.x (or later) kernel?  If so this would conclusively
>rule out a kernel issue.
>
>Regards
>  jonathan
>
>
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