Apparently Intel, in all of their brilliance, have decided that people using Ubuntu (and Linux in general) on laptops with an Intel wireless card simply must know when data is being transferred over wireless. It is of such paramount importance that you know this that Intel has decided to alert you by constantly blinking the wifi LED whenever data is being transferred. I think every other wireless card on the planet just has a solid LED light to indicate the wireless is on (or off, using the physical switch), but no, that’s not good enough for Intel. (Can you guess that the blinking light really annoys me?)

There’s no easy-to-find setting to change the LED to solid. But there is a solution: create a little script to change the LED to solid whenever you connect to a new wireless network. It’s pretty easy to do, too. Here we go:

1. Create a new file using Nano:
   user@computer:$ sudo nano /etc/network/if-up.d/wifi-led-noblink
   
2. Paste the following into your new file using ctrl+shift+v:
   #!/bin/sh
   #this script will prevent the wifi light from blinking when on.
   #to activate this script, create a soft link to it in /etc/network/if-up.d/
   echo none > /sys/class/leds/iwl-phy0::RX/trigger
   echo none > /sys/class/leds/iwl-phy0::TX/trigger
   echo none > /sys/class/leds/iwl-phy0::radio/trigger
   echo none > /sys/class/leds/iwl-phy0::assoc/trigger

   Press ctrl+x to quit Nano, then y to save your script.

3. Make the script executable:
   user@computer:$ sudo chmod u+x /etc/network/if-up.d/wifi-led-noblink
   

That’s it! Next time you connect to a network, your wifi LED should remain solid. This works in Karmic. And next time you find yourself cursing the guys at Intel, just remember: at least you don’t have a Broadcom wireless card!

2010-07-21 Update!

As of kernel 2.6.34 this solution no longer works for me. However, commenter DM has suggested an alternative that does seem to work again.

1. Create a new file using Nano:
   user@computer:$ sudo nano /etc/modprobe.d/wlan.conf
   
2. Paste the following into your new file using ctrl+shift+v:
   #1 means do not blink
   options iwlcore led_mode=1

   Press ctrl+x to quit Nano, then y to save your script.

3. Restart your laptop.

This different solution should work if the above solution doesn’t.

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