From: Steven G. <sga...@ce...> - 2007-11-09 01:09:35
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I have an 8 node verdex netwifi-microsd w/ consoleLCD-vx testbed. I was able to get both the ethernet and wifi working using buildroot version 1546 and the patches and instructions found here: http://docwiki.gumstix.org/Net-wifi-microusd After running some performance tests with various traffic loads I began to experience various ethernet and wifi failures. In some instances I can get the ethernet to drop out by doing a flood ping to a directly connected attached host. After a short period of time (minutes) all the pings fail and all ethernet network connectivity is gone. When this happens sometimes I see the following message on the serial console: NETDEV WATCHDOG: eth0: transmit timed out eth0: link down eth0: link up, 100Mbps, full-duplex, lpa 0x85E1 Most of the time if I remove the driver and reinstall it network connectivity is restored: # rmmod smc911x # rmmod gumstix_smc911x #<-- you get a big debug dump here # modprobe smc911x I have also been able to drop the wifi interface be doing a flood ping over the RF and over the LAN at the same time. When this happens the blue light on the netwifi-microsd board goes dark. PC <--ethernet--> gumstix1 <--RF--> gumstix2 Initially I was testing a 4 node network with a PC directly attached to each gumstix. Each PC sourced a 200Kbps multicast stream and subscribed to every other PC's multicast stream. The gumstixs serve as default routers forwarding the traffic across the wireless net. At this traffic load I started experiencing ethernet and wifi device failures randomly across all the nodes in my testbed. So I am _not_ leaning towards the theory that I have bad hardware, unless all my boards are bad. I started recreating the failures with flood pings to make it easier for others to experience my pain. During my initial investigation I found that on some of the LAN failures the gumstix was transmitting but it could not receive any traffic. A tcpdump on the attached PC showed an endless stream of gumstix arp requests and PC arp replies, but no one was listening. I have found references to ~similar~ items in mailing list archives but nothing as severe as I am experiencing. This thread contains some interesting thoughts, although it deals with the smc91x driver and is rather old: https://lists.ertos.nicta.com.au/archives/kenge-users/2007-February/000630.html Has anyone experienced behavior like this? I'd appreciate a point in the right direction or just some suggestions on possible causes. Thanks, Steven Notes: * I have tried the smc911x driver as a module and built into the kernel * DMA is definitely disabled |