[asterisk-ss7] MTP2 CRC errors resulting in flapping link

Patrick asterisk-list at puzzled.xs4all.nl
Tue Jul 4 01:15:46 MST 2006

Hi Kai,

On Tue, 2006-07-04 at 09:45 +0200, Kai Militzer wrote:
> Hello Patrick,
> Patrick wrote:
> > Digium cards are (were?) famous for not playing very nice when they had
> > to share interrupts with other hardware. Best practice is (was?) to have
> > the card on its own interrupt. Did you try to disable usb on the box and
> > disabling the uhci_hcd & ehci_hcd modules? What about disabling the
> > parallel port and the parport0 module (to free up as much interrupts as
> > possible)?
> As the box is located on a location I have to drive to for an hour, I 
> cannot disable USB in the BIOS that easy. The things I could do from 
> here, I have done so far, meaning I unloaded the uhci and ehci modules, 
> changed from an smp kernel to a non smp kernel and even to a standard 
> 386 kernel, disabled apic and acpi, loaded eepro100 instead of e100 and 
> unloaded the parport modules without any results.

Too bad. Would have been nice to have nailed this problem.
> > Since I see ide0 in your output check if you have set the right hdparm
> > settings for IDE. There are some tips on
> > http://www.asteriskguru.com/tutorials/pci_irq_apic_tdm_ticks_te410p_te405p_noise.html
> I was not able to enable DMA for my harddisk, as hdparm says it is not 
> able to set it. I suspect the problems may derive from a buggy 
> BIOS/mainboard.

That's odd. I'm not a harddisk/DMA expert but I thought that enabling DMA is
supported by most boards/disks these days. Is this perhaps a rather old PC you
are using? In that case, also check that the PCI revision implemented on the
board is really 2.2. I've read several times that anything lower will not
properly work. Digium cards *require* PCI slots at revision 2.2. 

> So far I have no more idead what I can do. If I don't get any other 
> ideas to solve this from any of you, I will try to disable USB physicaly 
> in the BIOS, but that will be my last resort.

Maybe try to update the BIOS too. If that does not work either and
unless someone comes up with a good idea, it seems it comes down to two

1) replace the Digium card with another E1 card
2) replace entire server with something new that is known to work well,
does not have shared interrupt issues like many Dells were reported to
have and has PCI 2.2 slots


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