To turn off the wireless signal you may apply one of the following methods.
Method 0: Remove battery
This is the fast method, for when a flight attendant is getting mad at you. Close the laptop, flip it over, slide the latches, and remove the battery. Poof, no more radio signal.
- If one does this, is there any chance of losing data or worse? My main concern would be with the file system. Is there anything special about the xo that fsck isn't required? On my system, build 656, there is /usr/sbin/fsck. If the xo loses power abnormally, will fsck run at the next boot? My browser crashes often and my journal entries are messed up. If I want to run fsck, where do I find further info. I can't find anything about it under olpc wiki. BobUgh 19:29, 24 June 2008 (UTC)
Method 1: Disable wireless temporarily until next reboot
This method will turn the radio off only until the next reboot. So there is an issue when during a flight your XO is turned off. Naturally, the 802.11 wireless radio does not interfere with the aircraft controls, and you can simply turn your XO on, wait until it boots and disable the radio then. If you want to avoid this, you can disable the radio when still on land and keep your XO turned on or suspended to save power. Alternatively you can disable the radio permanently as described in Method 2.
- To turn the radio off go to Terminal activity and type:
sugar-control-panel -s radio off
- To turn it back on go to Terminal activity and type:
sugar-control-panel -s radio on
Method 2: Disable wireless permanently (across reboots)
This method will keep the radio off even after reboots. Therefore you can turn the radio off when on land and turn the XO off as well until you need to use it. When landed you can recover the radio back to normal.
- To turn the radio off go to Terminal activity or Virtual Terminal and type:
su /sbin/rmmod usb8xxx mv /lib/firmware/usb8388.bin /lib/firmware/usb8388.bin.quiet # This takes effect immediately. There is no need to reboot.
- To turn it back on go to Terminal activity or Virtual Terminal and type:
su mv /lib/firmware/usb8388.bin.quiet /lib/firmware/usb8388.bin rmmod usb8xxx sleep 1 modprobe usb8xxx # You will likely need to reboot for wireless to resume.
Neither of these last two methods reduces the power draw of the wireless chips. OLPC hopes to be providing a GUI interface that will not only turn it off, but also stop it from burning up your battery. The chips burn more power than they were designed to, and the vendor is disinclined to fix this. The power supply to the chips cannot actually be turned off, due to a hardware design defect; but the chips can be forced into "RESET" indefinitely, and they take much less power in that state. See ticket #6935
10-05-08 Added by JD: Hmmm... according to http://wiki.laptop.org/go/Feature_Longer_battery_life, the "Extreme Power Management" feature does indeed reduce the radio chip power draw. Please clarify.