Debian Tips
R. Checa-Garcia (CC BY-NC-SA) COMPUTING-BLOG
Linux Debian
Tips
My own daily use computer is a Lenovo Thinkpad T440s and I have installed only a Debian Linux distribution, in particular the testing version, this means that usually I have to solve by myself tipical problems that the stable distribution doesn’t have. Here I am including a list of those problems that I was able to solve, maybe alone maybe with the help of several forums in internet.Table of Contents
December 2015: iwlwifi
In Dec-2015 there were an update of the non-free package that control the intel wifi card ensembled on the Lenovo T440s, however the update broked my internet wifi conection. Here you have several steps to solve the problem:
Diagnosis
A first step is try to see what is happening:dmesg | grep wifi
When this command is used we detect that Debian is trying to find a file named: iwlwifi-7260-7.ucode and looking on the webpage of debian concerning T440s we realize that the Network Controller,Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b2] (rev 83)
In my case the documentation about T440s is not including this information but T440p that is basically the same laptop covers all the steps for Debian installation Debian-T440p. Another source of information is ThinkWiki.
Checking Diagnosis
Our first guess is a problem with iwlwifi, so simply we check the files installed by this debian package. You can find this information on the link: FileList-iwlwifi. We can realize that the iwlwifi-7260-7.ucode is not in the list of files installed. We can double check this withls /lib/firmware/*ucode
Solving the problem
Now we can check the stable equivalent package at Stable-version-iwlwifi and confirm that iwlwifi-7260-7.ucode is there. Therefore simply download here the files on this package firmware-nonfree_0.43.tar.gz. Wa can extract the file named iwlwifi-7260-7.ucode-22.1.7.0 and copy at /lib/firmware with the name iwlwifi-7260-7.ucode. You can simply reboot the machine and the wifi is alive again.