How to stop constantly blinking Wifi LED?

Turning LED blinking off for Intel Wireless Cards (and some Atheros)

Note: based on an extensive study of all in-kernel wireless drivers (i.e. compat-wireless, only Intel cards and one Atheros chipset support module options to control LED behavior. Note that the actual LED control code in most drivers is fairly simple, so if you have basic familiarity with C, building kernel modules and reading the occasional datasheet, it's pretty easy to disable LED blinking for almost any wifi card with an open-source driver.

• Press Alt+F2, and type gksudo gedit /etc/modprobe.d/iwled.conf (or open this file in your favorite editor)
• Add the line options MODULE_NAME led_mode=1
  • MODULE_NAME is listed below for your Ubuntu version and your card model
  • Replace led_mode with the appropriate option if it is indicated, for the Intel 2200BG/2900ABG or Atheros cards
• Save and exit the editor; reboot

1. Ubuntu 13.04 (Raring Ringtail) - kernel series 3.8

• iwlwifi for Intel Centrino Wireless-N series 1xx, 1xxx, 2xx, 2xxx, 5xxx, 6xxx
• iwlegacy for Intel Wireless series 3945 (tested), 4965
• ipw2200 with led=0 for Intel Pro/Wireless 2200BG, 2915ABG
• ath9k with blink=0 for Atheros wireless cards using the ath9k driver

2. Ubuntu 12.04 (Precise) - kernel series 3.2

• iwlwifi for Intel Centrino Wireless-N series 1xx, 1xxx, 2xx, 2xxx, 5xxx, 6xxx
• iwl-legacy for Intel Wireless series 3945, 4965
• ipw2200 with led=0 for Intel Pro/Wireless 2200BG, 2915ABG
• ath9k with blink=0 for Atheros wireless cards using the ath9k driver

3. Ubuntu 11.10 (Oneiric) - kernel series 3.0

• iwlagn for Intel Centrino Wireless-N series 1xx, 1xxx, 2xx, 2xxx, 5xxx, 6xxx
• iwl-legacy for Intel Wireless series 3945, 4965
• ipw2200 with led=0 for Intel Pro/Wireless 2200BG, 2915ABG
• ath9k with blink=0 for Atheros wireless cards using the ath9k driver

4. Ubuntu 11.04 (Lucid) - kernel series 2.6

• iwlcore for Intel Centrino Wireless-N series 1xx, 1xxx, 2xx, 2xxx, 3945, 4965, 5xxx, 6xxx
• ipw2200 with led=0 for Intel Pro/Wireless 2200BG, 2915ABG
• ath9k with blink=0 for Atheros wireless cards using the ath9k driver

5. Ubuntu 10.04 (Lucid) - kernel series 2.6

• The default for supported Intel Centrino cards in 10.04 is to simply keep the LED on if wireless is on (and off otherwise), so this "mod" should not be needed (thanks htorque!)
• ipw2200 with led=0 for Intel Pro/Wireless 2200BG, 2915ABG
• ath9k with blink=0 for Atheros wireless cards using the ath9k driver

1. Open the terminal:

   Applications > Accessories > Terminal or Ctrl + Alt + t

2. Enter the following in the terminal:

   gksudo gedit /etc/modprobe.d/wlan.conf
   

3. Copy and paste the below line:

   options iwlcore led_mode=1
   

4. Save the file.

5. Restart the laptop.

This is a known bug: Bug #250211