Linksys WMP54G EU segmentation fault and connection problems

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12-06-2008 09:58:34


System config PCI Linksys WMP54G EU, Ubuntu 8.4, latest cvs rt61 driver (the stable or beta releases do not work here), the access point is Linksys WRT54GSV4 (works just fine with my windows laptop, so the signal should be good enough).

After system startup i run the following script:
ifconfig wlan0 down
#iwconfig wlan0 essid ""
iwconfig wlan0 mode managed
iwconfig wlan0 ap 0016B6016008
iwconfig wlan0 essid linksys_boza
iwconfig wlan0 bit 18M
iwpriv wlan0 set AuthMode=WPA2PSK
iwpriv wlan0 set EncrypType=AES
iwpriv wlan0 set WPAPSK=removed
#iwconfig wlan0 essid linksys_boza
iwconfig wlan0 ap 0016B6016008
ifconfig wlan0 up
route add -net default gw

The problem Although I specify the encryption key with iwpriv (as instructed in the README), iwconfig returns that wlan0 uses no encryption key and the output is like this
wlan0 RT61 Wireless ESSID"linksys_boza" Nickname""
ModeManaged Frequency2.422 GHz Bit Rate=18 Mb/s
RTS throff Fragment throff
Encryption keyoff
Link Quality=54/100 Signal level-75 dBm Noise level-111 dBm
Rx invalid nwid0 Rx invalid crypt0 Rx invalid frag0
Tx excessive retries0 Invalid misc0 Missed beacon0

Consecutive calls to iwconfig sometimes show the interface using another ESSID (there are around 10 other visible networks around here), displaying sometimes the mac address of my AP, hiding it again, then showing it again etc. This can go on for hours. If you try rerunning the script that brings up the interface and configures it again, the chance is big to see the line "segmentation fault" after which the system cannot be shut down, no programs can be started and the only possibility is to cut the power. This actually happens on "ifconfig wlan0 down" and it should be the kernel itself that is pushed by the driver to segfault as everything else stops working as well.

Doing "iwlist scan" lists my AP with its mac address, I don't really see why the interface cannot connect to the AP that is actually visible.

Sometimes, like right now, the key is finally displayed in iwconfig wlan0 Encryption key8-times-4-hex-numbers and after awhile the interface connects to the AP, although the green lamp near the antenna does not light immediately.

The connection speed also varies a lot - setting the bitrate at 18M seems to be optimal for the moment, resulting in 80-400KBytes/s, although the ISP provides 2.4MBytes/s downstream but that's something I can live with.

So, any ideas how to solve this, what more needs to be done? Thanks in advance.


13-06-2008 18:25:24

Hi mtm2,

Could you build and run with debug enabled, then gzip the section of /var/log/kern.log covering the interval between modprobe and the segmentation fault, and attach it to a posting here? A gzipped copy of /var/log/debug for the same interval would also be helpful.