OLPC "iperf hang" notes

[Marcelo Tosatti]

On Wed, Feb 28, 2007 at 02:03:44PM -0800, David Miller wrote:
> From: Mitch Bradley <wmb at firmworks.com>
> Date: Wed, 28 Feb 2007 12:00:35 -1000
> 
> > I also used "ifconfig" and "netstat -s" to look for errors detected by 
> > the network stack.  After each iperf run, the ifconfig "TX dropped" 
> > number increased by 9
> 
> Looks like the retransmits on the sender side are being
> dropped at the device.
> 
> I've never seen this behvaior reported by anybody, ever,
> so this is increasingly looking like a driver/hardware
> problem, not a TCP one.

Problem still happens with recent (-rc2) kernels.