升级到 Ubuntu 12.04 后 Broadcom Wireless 无法工作

Question

我已经升级到 Ubuntu 12.04 但我的无线不再工作了。

以下是有关该系统的一些信息：

$ cat /etc/modprobe.d/* | grep bcm
# Warning: This file is autogenerated by bcmwl. All changes to this file will be lost.
blacklist bcm43xx

blacklist bcma
#blacklist bcm43xx
blacklist bcm43xx

$ sudo gedit blacklist.conf

[sudo] password for alexandre: 

$ rfkill list all

0: acer-wireless: Wireless LAN

    Soft blocked: yes
    Hard blocked: no

$ rfkill unblock 0

$ rfkill list all

0: acer-wireless: Wireless LAN
    Soft blocked: no
    Hard blocked: no

$  lspci -nn | grep 0280

06:00.0 Network controller [0280]: Broadcom Corporation BCM4311 802.11b/g WLAN [14e4:4311] (rev 01)

电脑 Acer Aspire 5315。有什么办法可以解决这个问题吗？