Update (2012-04-26): On a new install of Ubuntu 12.04 I was able to connect to my wireless network without any additional configuration.
After lots of time fighting to get my wireless going for my U400 in Ubuntu 11.10 (more specifically, Kubuntu 11.10), here’s what I’ve learned. (This may also apply to the U300 & U300s)
Before installing Ubuntu, make sure that the wireless is working under Windows, specifically that the hardware switch (Fn + F7) is set to on. If it’s set to off, you’ll be forced to reinstall Windows to do it – apparently there’s currently no way this can be done within Linux on this laptop.
You can verify that this is done correctly by putting in the command rfkill list into the terminal and seeing something like the following. Note that what you’re looking for now is that nothing is hard blocked, it might still be soft blocked, but the next steps should take care of that.
colby@colby-laptop:~$ rfkill list 0: ideapad_wlan: Wireless LAN Soft blocked: no Hard blocked: no 1: ideapad_bluetooth: Bluetooth Soft blocked: no Hard blocked: no 3: phy0: Wireless LAN Soft blocked: no Hard blocked: no 4: hci0: Bluetooth Soft blocked: no Hard blocked: no
To get it working temporarily:
This is more for trying out a live CD, etc.. Run this command in the terminal:
sudo modprobe -r acer_wmi
and you should have wireless for your session.
To make this permanent:
Open up /etc/modprobe.d/blacklist.conf with your favorite text editor, for example:
sudo nano /etc/modprobe.d/blacklist.conf
and add to the bottom:
And that should be it. Restart and you should still have wireless. Hopefully this helps someone. If I’ve omitted something important, please visit the forum or comment below and tell me so I can correct the article.
If your U400 seems to be running way hotter than it should be under Ubuntu, check out this article.