Re: [RFC PATCH] firewire: ohci: disable MSI on Agere/LSI FW643 rev 8

Hi,

On Sun, Jul 19, 2026 at 01:22:40PM -0700, Tchirek Afra wrote:
> While reading ohci.c, I also found commit 0d12f095b439:
> 
> https://github.com/torvalds/linux/commit/0d12f095b439
> 
> It enabled busReset in the initial interrupt setup. My failed dump had
> busReset and selfIDComplete pending after the MSI counter stopped, so
> there may be a timing issue there as well. I want to understand that
> before sending a v2.

It's the part of series to support tracepoints events[1]. The reason is
to handle the busReset event in 'trace_irq()'[2] for 'irq' event of
'firewire_ohci' subsystem in Linux tracepoints framework. It depends on
userspace operation, and to obsolete the 'debug' module parameter.

As you know, during handling selfIDComplete event, the busReset event
should be suppressed. But except for the suppression, it has no side
effect to enable busReset event as long as I know. However, I'll check
1394 OHCI specification later so that there is no overlooking.

[1] https://lore.kernel.org/lkml/[email protected]/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/firewire/ohci.c?h=v7.1#n2076


Thanks

Takashi Sakamoto