Re: Multiple Mantis devices gives me glitches

[Vidar Tyldum <vidar@tyldum.com>]

(sorry for breaking the threading, the reply came faster than my
subscription to the list :)

>From Ninja <Ninja15@xxxxxx>,
> Hi, I noticed some SMP problems with the mantis driver as well (see my
> post "Mantis CAM not SMP safe / Activating CAM on Technisat Skystar HD2
> (DVB-S2)"). One workaround for me is to limit the CPU to one core (to be
> sure disable the hyperthreading cores as well). That can be done via BIOS
> *or* adding maxcpus=1 as kernel parameter *or* you can disable the cores
> one by one via "|echo 0 > /sys/devices/system/cpu/cpuX/online|" where X
> is the core to disable. Since you need to be root for this, I did "sudo
> su" first. But of course our problems might be completely unrelated and
> limiting to one core won't change a thing ;)
> 
> Manuel

I doubt I'll revert back to the stock mantis module to test right now, but
your suggestion and observations might certainly be of interest. If/when
Ubuntu releases a new kernel which overwrites my current driver I will give
it a go.
However, instead of disabling SMP completely I hope adjusting IRQ affinity
could be sufficient:
  http://kernel.org/doc/Documentation/IRQ-affinity.txt

Couple this with increased PCI latency might work, however with three
devices connected I think the only solution is to reduce the number of
interrupts (though I am by no means any expert on this subject).

-- 
Vidar Tyldum
                              vidar@tyldum.com               PGP: 0x3110AA98