On Sat, Jan 23, 2021 at 12:59:29PM +0100, David Runge wrote: ... > > Unfortunately firewire-ohci is unable to initialize my firewire > controller [1] (a PCIe card [2]) both on 5.4.91-rt50 and on 5.10.8-rt24: No > device nodes (i.e. /dev/fw0) are created and therefore no connected devices can > be initialized either. > ... > At this point in time I'm uncertain whether this is a general problem > with the kernel module on the realtime kernels or a problem with the > kernel module on the realtime kernels with my PCIe controller specifically. > That it works using the ExpressCard34 based controller on my laptop makes it > extra odd (but I guess the underlying driver is handling this > differently due to the PCI bridge?). > Can you please send the full kernel log, with boot parameter "firewire_ohci.debug=-1", for mainline v5.4.91 vs. v5.4.91-rt50? Please also make sure to use the exact same defconfig for both, except with CONFIG_PREEMPT_RT=y for the -rt kenrel of course. This will help in comparing apples to apples, as you were posting the results of different base kernels (vs. the -rt versions), and different defconfigs (vs. -rt) within such kernels. Good luck, P.S. Since this maybe is a timing issue, and ohci bus reset handling occurs at SCHED_OTHER workqueu context, were you by any chance running unreasonably-intensive realtime workloads by the time the driver was loaded? Thanks, -- Ahmed S. Darwish
