Re: ne2k-pci uncorrectly detecting collisions ?

From: Lucas Nussbaum
Date: Wed May 05 2004 - 08:17:54 EST


On Wed, May 05, 2004 at 09:00:50AM -0400, "Richard B. Johnson" <root@xxxxxxxxxxxxxxxxxx> wrote:
> > I have experienced problem with the ne2k-pci driver. The symptoms were
> > extremly poor performance with TCP. After some investigations, I believe
> > it might be caused by problems with detecting collisions.
> >
>
> But software doesn't detect collisions. It just records what
> hardware said it did. It looks like you have a 10 Mb/s card
> on a 100 Mb/s network. The collisions reported are how the
> hardware throttles the difference in physical-link speed.

The hub is a 10/100 one, and the 3 RTL8029 are 10 Mbps only.

> It is possible that software didn't initialize a 100 Mb/s
> device and instead initialized it to 10 Mb/s, but you
> don't have any evidence of that presented.

No, because RTL8029 are 10 mbps only (they are BNC/RJ45 NICs).

But what I thought was that maybe, they were initialised as full duplex,
not half duplex. But again, I don't know where I can check that. I added
some printks and determined that the code used to init them full duplex
was never used. And there's no way to force them half duplex with this
driver.

Lucas
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