[vortex] Rx overruns with 3c575 Cyclone on CardBus

[Bogdan Costescu]

On Wed, 14 Jul 2004, Norbert Crombach wrote:

> ifconfig shows a load of Rx overruns, and no data gets through.

Rx overruns happen when the system is not able to take fast enough the 
packets that come from the network and the driver buffers are filled 
up. However, this situation should clear itself up after some time, 
when the system load decreases, unless the system is subject to a 
storm of packets.

> The only thing that seems to help is to reinsert the card in the
> CardBus slot (configuration is done automagically).

This most likely indicates an interrupt problem. The scenario 
described above (clearing of the Rx overruns) cannot happen if the 
interrupt requests generated by the card do not result in the driver's 
interrupt routine being run. Then the buffers are not emptied and the 
card will not be able to accept new packets.
Most often than not, this proved to be a problem of the PCMCIA 
subsystem in Linux rather than the 3c59x driver; look up the list 
archives, this is not the first time it is mentioned...

-- 
Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu at IWR.Uni-Heidelberg.De