[ltp] iwl4965, Hardy x86_64, and frustration (long)

[John Jason Jordan]

I have had  my T61 with nVidia and 4965agn wireless for over a year. In
all that time I have run only Ubuntu x86_64. 

Some additional facts:
At home my house is wired for ethernet and I have a cable connection,
so wireless is not only not needed, there is no wireless network to
connect to. Having said that, the neighbors have wireless and their
networks are visible, even if they are secured so I can't connect to
them. In order to test wireless I have to go to the university, a
coffee shop, or some other location. Unless I make a special trip, this
happens two-three times a week.

The problem:
Right from the beginning (Feisty, x86_64 through Gutsy x86_64) the
4965agn did not work well. I could connect, but I would get disconnects
(random, not timed). The weaker the signal the faster the disconnect. I
could not tell that I was disconnected until suddenly I could not go
anywhere. Network Manager would always say I was connected and would
show the IP address for DHCP. Ditto for Wifi-Radar. After much research
I figured out that I was still connected to the access point, but had
lost my DHCP lease. Yet the command line and the GUIs insisted that I
was connected and had an IP address.

To fix the problem I used a number of tools. I could kill Network
Manager and restart it, but this restored the DHCP lease only
occasionally. Doing "ifconfig wlan0 down" then "up" occasionally
restored the connection, although not usually.
"Sudo /etc/init.d/networking restart" would sometimes get me going
again, but usually not. "Modprobe -r iwl4965," followed by reinserting
it, would also occasionally work. If I poked at the problem repeatedly
with these tools I could restore the connection most of the time, but
not always.

System > Administration > Network showed the wireless connection. It
was set by default to roaming mode. (Side comment: I have searched all
the Ubuntu forums without finding a definition of what the hell
"roaming mode" means. It must mean my cell phone company will charge me
extra for time connected via wireless, but that doesn't make sense.)

If i change the wireless connection from roaming mode I have to enter a
network access point and set it to DHCP or something. To do so I need
to select the wireless device, then click on Properties, then uncheck
the roaming mode box. It won't accept the new settings until I give it
an access point. But when I click on the drop-down the available
networks to connect to appear only about one time out of 20-30 tries.

If i use Wifi-Radar it shows all available networks every time.
However, selecting one and telling Wifi-Radar to connect to it works
only one out of 5-10 tries. I also installed Kwifimanager, but got more
or less the same results.

Because of the vexation with the 4965agn I borrowed a Netgear WG511T
PCMCIA card from a friend. It always works just fine. 

Until recently the LED never came on either, whether using the built-in
4965 or the Netgear. (See below.)

-----------

Upgrade to Hardy

Last Thursday I upgraded Gutsy x86_64 to Hardy x86_64. Right from the
beginning there was no difference in the wifi problem. However, I was
at home and could only poke at Network Manager and Wifi-Radar to see if
they found any wireless networks. Network Manager and Wifi-Radar saw no
available networks. And the LED did not come on. That is, until Peter
Frühberger here told me to install:

linux-backports-modules-hardy-generic
linux-backports-modules-2.6.24-16-generic <- meaning the one matchin to
your kernel

Having followed his advice the LED now comes on. Other problems remain,
that is, I cannot get a reliable wireless connection.

Following advice of others, last night I installed Wicd. Installing
Wicd automatically uninstalls Network Manager and Wifi-Radar. After
installing it there seemed to be no change. Wicd could not see any
wireless networks either. Bear in mind that I was at home where I am on
ethernet.

Today I went to the university. As soon as I was booted up I launched
Wicd. And lo and behold, it displayed all available networks.
(Evidently it failed to do so at home because I was already connected
at the time via ethernet.) I selected the student network
(pubnet.pdx.edu) and a few moments later I was connected with an IP
address. I was happily able to go anywhere on the net. And about an
hour later suddenly I wasn't going anywhere again. Lost the DHCP lease.
Same problem as before. At the time I was sitting directly under an
access point.

Meantime, I hear form a number of people who say have the 4965agn card
working fine. In all cases so far, they are using a different distro, a
32-bit architecture, or are really running a 3945 instead of a 4965, or
something else significant is different.

I have googled and found a number of posts about the random
disconnects. All are over a year old. None say what they did to fix the
problem, or if their fix involved throwing the T61 in the river and
buying a different laptop.

------------

Suggestions needed:
I would be happy to post back the response from any command line
commands if such would help people diagnose the problem. I am not
extremely knowledgeable about networking, but can follow detailed
instructions faithfully.

If someone has the 4965agn working without a problem in 64-but Hardy, I
would appreciate any insights you can offer.