WiFi on Linux paper (again)

[Karl Larsen]

    I tried to get this improved version on the Fedora Portal but it is 
broken. So here it is again. And again if you see something wrong or a 
change you would like to see pass it along. I have fixed a lot of 
grammatical errors. They are a part of a new paper. You just through 
things in.


        How to get WiFi working on your lap-top

    It has been hard to get the wifi that works so well on your Windows 
XP to work when you select Linux at boot time. Windows XP has nothing 
that helps you to get Linux working. In this paper you will see that 
there is a step by step process that is most efficient getting your 
system working.

I:    First, in this example I MUST learn what the name of my WiFi 
hardware. This can usually be done from a root Terminal and you 
call        # lspci. This will print a list of all the pci things in my 
Sony laptop.

00:09.0 Ethernet controller: Atheros Communications, Inc. AR5212 
802.11abg NIC (rev 01)
00:0a.0 CardBus bridge: Texas Instruments PCI7420 CardBus Controller
00:0f.0 IDE interface: ALi Corporation M5229 IDE (rev c4)
00:12.0 Ethernet controller: Realtek Semiconductor Co., Ltd. 
RTL-8139/8139C/8139C+ (rev 10)

Notice there are two items called Ethernet controller. But notice the 
Atheros says it handles 802.11abg which is what WiFi is, So now we know 
this laptop has hardware made by Atheros Communications, Inc.

II:    The second step is to find out what Linux software is written for 
your hardware. I used a great web page at:

http://linux-wless.passys.nl/

I went to this web page and at the first choice selected Sony. I then 
hit Show and in the green band was Atheros and it says I need the 
MadWiFi package and directs me to their web page. There you look at the 
HowTo page and learn the actual kernel module is called "ath_pci" and 
that call will get it working and it will call all the other needed 
modules. The next step is to find a kernel with this software in it that 
will make my laptop work.

III:    Now find a kernel that has my drivers in module form. Start with 
your current kernel and as root type # modprobe ath_pci. If nothing 
happens I am lucky, my kernel has the driver I need. Check with # lsmod 
and see what modules were installed. In a more general case modprobe says:

[root at k5di ~]# modprobe ath_pci
FATAL: Module ath_pci not found.

Then you need to find a kernel with your modules or add the module(s) to 
your kernel. Try older and newer kernels and try a Google search. To end 
this example case I found that fedora 2.6.21-1.3232.fc7 has ath_pci 
within it. I turned off network and turned on NetworkManager and 
NetworkManagerDispatcher and rebooted. To my great delight it came up 
with NetworkManager telling me I was connected to my WiFi source.

IV:

    Listed next is four laptop hardware systems I know about.

  Hardware              Software        modprobe    

  Atheros Comm           madwifi        ath_pci
   
  Intel old              IEEE80211      ipw2200   

  IntelPro 3945          IEEE80211      ipw3945   

  Broadcom BCM 4318      MAC80211       bcm43xx


V:    There is a network system available in at least Fedora Core 6 and 
Fedora 7 called NetworkManager. You will want to set that up at least on 
your laptop. I have it on both computers. Caution! Turn off network if 
your using NetworkManager. Be aware that not everyone likes this 
software and some say that it will not work well with some WiFi systems. 
I can only say it works just fine for me.

    Do this, cd /etc/rc.d/init.d/ and you will see a lot of applications 
listed. Now as root do # chkconfig network off and then
# chkconfig NetworkManager on and # chkconfig NetworkManagerDispatcher 
on. Reboot and my new system was working.

    When you have the right kernel you can now use # modprobe ath_pci 
and that will work. Look at the two tiny computers near your name on the 
top edge and click on them. It will tell you about what it is doing. 
Also use the # nm-tool which will show you what Internet it is working 
on and what is turned off.

    Follow the same steps I did with my laptop and replace mine with 
yours. I hope your laptop is using one of the about 50 hardware packages 
in the the web page above. And you wind up quickly with a working Linux 
laptop.

If you know about other Linux software please write. If you have a 
laptop that is working and you forgot what you did, do this:

# lsmod and find the ones that sound like wifi stuff. Or look at 
/etc/modprobe.conf and you should see them there. Include the kernel you 
are using.

Karl Larsen