bge(4) one packet wedge

[Julian Elischer]

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 
>

Is there any IPMI set up on the machine?
is it possible that some extra circuitry involved with ipmi is holding 
the packet?

>sent ping.
>
>  
>