[vortex] causes 3c905c jitter ???

[Stefan Doehla]

Hi!

I have here a realtime application with RTLinux. It seemed to me that 
some PCI cards vblock from time to time the PCI bus. E.g. video cards 
tend to use the pci_retry feature of the PCI spec -> PCI bus is locked 
for some microseconds. This problem was solved with a downgrade to XFree 
3.3.6.

To my problem: XForwarding and some other network stuff (which should be 
used later in conjunction with the realtime programs) causes also 
jitter. It seems like the softwareside is okay.
It looks like only outgoing traffic causes problems ...

Can the 3com networkcard lock the PCI bus for some microseconds? Uses it 
a fifo that's not checked before writing (due to performance gains)?

If yes to any of the above things: Can I pass options to the module to 
be more friendly to realtime things (a loss of performance is not so 
important)? Will the 3com driver instead of the Linux driver help?

Thanks for any information,
Stefan