bge(4) one packet wedge

[Oleg Bulyzhin]

On Wed, Aug 23, 2006 at 10:26:48PM +0400, Oleg Bulyzhin wrote:
> On Wed, Aug 23, 2006 at 08:16:49PM +0400, Gleb Smirnoff wrote:
> >   Colleagues,
> > 
> >   I've faced a problem in bge(4) when a single packet is in the RX
> > ring, but it isn't noticed by the driver. A reception of a packet
> > triggers interrupt and both packets are processed - an old one
> > and the new one.
> > 
> >   To reproduce the problem you need to run netperf (from ports
> > collection): netserver on another host (10.0.0.1) and netperf on
> > the host, where tested bge(4) is installed - 10.0.0.2. No traffic
> > except netperf's should flow through this NIC, or the problem won't
> > be reproduced!
> > 
> >   So, I run netperf client and simultaneously tcpdump on the
> > another host. After few seconds there is a wedge. The last packet
> > seen on 10.0.0.1 is the packet sent by 10.0.0.1 to 10.0.0.2. However
> > it isn't seen on 10.0.0.2.
> > 
> > Ok, let's look at the receive ring:
> > 
> > (kgdb) p $sc->bge_rx_saved_considx
> > $14 = 51
> > (kgdb) p $sc->bge_ldata.bge_status_block->bge_idx[0].bge_rx_prod_idx
> > $15 = 51
> > 
> > Looks like there is nothing to process.
> > 
> > However, if I run 'ping -c 1 10.0.0.2' I will get an interrupt and read
> > two packets: first the old packet, and then recently sent ping.
> > 
> > -- 
> > Totus tuus, Glebius.
> > GLEBIUS-RIPN GLEB-RIPE
> 
> What happens if you trigger other interrupt (like unplug/plug cable)?
> Will you get that packet?
> 
> -- 
> Oleg.
> 
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Does polling(4) solve the issue?

-- 
Oleg.