After compiling kernel wifi doesn't work

The tittle pretty much explains it, my wifi stopped working after I was done compiling the kernel on my T61. I used kernelcheck to do it.

Also, is there a place that explains some of the questions that it asks while running it? It asks a ton of them and its hard to know what to do. I used that kernel check program thinking it would answer them for me but it didn't.

One more thing, Linux is a really time consuming hobby

 

Stop compiling kernels and it won't consume so much of your time!

Also, stop consuming kernels in your popcorn as well!

 

The wifi driver for your Intel 4965 is the iwlwifi one which requires specific kernel options to be set in your kernel config. I'm not familiar with the kernelcheck tool, but it may have turned some of these options off when you ran it. The easiest, (and probably recommended), thing to do would be to go back to your previous kernel and/or installation, that enabled your wifi. If you need to you can go to the Ubuntu forums and look to see if someone has a step by step process for enabling the iwlwifi drivers for your wifi. Then you should ask there on the kernelcheck threads, when kernelcheck will support the iwlwifi driver kernel options, and wait until that time to use that tool.

If you don't want to roll back to your previous known good kernel, you can manually scan your current kernel configuration file with the following commands. (You can do them one at a time);

Code:

cat /usr/src/linux/.config |grep CONFIG_CFG80211
cat /usr/src/linux/.config |grep CONFIG_MAC80211
cat /usr/src/linux/.config |grep CONFIG_IEEE80211
cat /usr/src/linux/.config |grep CONFIG_WLAN_80211

You would be looking for responses like;

Code:

CONFIG_CFG80211=m
CONFIG_MAC80211=m
CONFIG_IEEE80211=m
CONFIG_WLAN_80211=y

If you see that any of them that state "is not set", then you can change that by editing the text file and changing it to "m" or "y". You would then need to manually build your kernel and install it again. If you run the kernelcheck tool, it would likely overwrite your manual changes and rebuild a kernel which wouldn't work for you.

Good Luck..

 

It is very unlikely that just compiling a new kernel would stop your wifi working, but maybe that kernelcheck script is doing odd things. OTOH if you compiled a new kernel, installed that kernel, and then rebooted, then that could easily account for why your wifi does not work any more.

It depends what type of wifi driver you are using, if you are using an ndiswrapper with a M$ driver, then you have probably not configured your kernel correctly. If you are using a kernel module from the "restricted" software section, then these are compiled against a particular kernel version (like all linux drivers), and more than likely will not work with a later kernel version. If you want your wifi to work with a newer kernel, then you'll have to download the wifi driver source from the relevant site and compile it.
The third possibility is that you have tried to upgrade to a kernel where the wifi in the kernel has been upgraded significantly and requires later software tools e.g. the wireless tools.

I can't think of any reference that will explain all the kernel config options and what combinations you need, best you can do is read the help associated with each of the config options and search the web.

You could also search to see if anyone has published their kernel .config for an IBM T61 with the same component hardware as in your laptop (e.g. two T61s could have different wifi chips).

For a book, you could take a look at "Linux Kernel in a Nutshell", http://www.kroah.com/lkn/ and remember that the Ubuntu distro will have it's own scripts for compiling a kernel.