How to debug PCI issues?

How to debug PCI issues?

[Ben Greear]

I'm working with a TYAN Tomcat board (i815, Ghz CPU).  It's in a 1U
machine with a butterfly riser so that I get two riser connections to
one PCI slot.  When I put Intel EEPRO nics in each slot, I can pass
30Mbps of traffic on each NIC without dropping a single packet
(In two days of running).

If I run 20Mbps on one of the DLINK ports, I'm fine, but if I run 10Mbps
on two of the DLINK ports, I start seeing dropped packets on every
interface, and port errors like RX-FIFO.

So, I'm thinking that the DLINK NIC must be screwing up the PCI
bus somehow when more than one of it's interfaces is passing any
significant traffic.  I have been able to run 10Mbps on all 8 ports
of two DLINKs on an Intel EEA2 (i815) board, so I suspect the MB.

Does anyone have any ideas how to go about trouble-shooting this
farther?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>          <Ben_Greear@excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear

Re: How to debug PCI issues?

[Francois Romieu]

Ben Greear <greearb@candelatech.com> :
[...]
> So, I'm thinking that the DLINK NIC must be screwing up the PCI
> bus somehow when more than one of it's interfaces is passing any
> significant traffic.  I have been able to run 10Mbps on all 8 ports
> of two DLINKs on an Intel EEA2 (i815) board, so I suspect the MB.
> 
> Does anyone have any ideas how to go about trouble-shooting this
> farther?

Check the pci latency timer settings for the devices are the same
on the two mobos and force them with setpci if they aren't.

-- 
Ueimor

Re: How to debug PCI issues?

[Martin Josefsson]

On Thu, 27 Sep 2001, Ben Greear wrote:

> I'm working with a TYAN Tomcat board (i815, Ghz CPU).  It's in a 1U
> machine with a butterfly riser so that I get two riser connections to
> one PCI slot.  When I put Intel EEPRO nics in each slot, I can pass
> 30Mbps of traffic on each NIC without dropping a single packet
> (In two days of running).
> 
> If I run 20Mbps on one of the DLINK ports, I'm fine, but if I run 10Mbps
> on two of the DLINK ports, I start seeing dropped packets on every
> interface, and port errors like RX-FIFO.

If I run traffic out one port I can get 100Mbit but if I try it with two
ports at the same time I cet about 20Mbit per port at best. And I also get
a _lot_ of errors but mostly carrier-errors.

> So, I'm thinking that the DLINK NIC must be screwing up the PCI
> bus somehow when more than one of it's interfaces is passing any
> significant traffic.  I have been able to run 10Mbps on all 8 ports
> of two DLINKs on an Intel EEA2 (i815) board, so I suspect the MB.
> 
> Does anyone have any ideas how to go about trouble-shooting this
> farther?
> 
> Thanks,
> Ben
> 
> -- 
> Ben Greear <greearb@candelatech.com>          <Ben_Greear@excite.com>
> President of Candela Technologies Inc      http://www.candelatech.com
> ScryMUD:  http://scry.wanfear.com     http://scry.wanfear.com/~greear
> -
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/Martin

Never argue with an idiot. They drag you down to their level, then beat you with experience.