我在 Ubuntu 16:04 64 位上遇到了 Wi-Fi 问题。从 15.10 升级到 16.04 后，问题就开始出现了。我尝试重新安装 Wi-Fi 驱动程序，但出现了错误：
sudo apt-get install --reinstall bcmwl-kernel-source：
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/1.515 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 286139 files and directories currently installed.)
Preparing to unpack .../bcmwl-kernel-source_6.30.223.248+bdcom-0ubuntu8_amd64.deb ...
Removing all DKMS Modules
Done.
Unpacking bcmwl-kernel-source (6.30.223.248+bdcom-0ubuntu8) over (6.30.223.248+bdcom-0ubuntu8) ...
Setting up bcmwl-kernel-source (6.30.223.248+bdcom-0ubuntu8) ...
Loading new bcmwl-6.30.223.248+bdcom DKMS files...
Building only for 4.4.0-22-generic
Building for architecture x86_64
Building initial module for 4.4.0-22-generic
Done.
wl：
Running module version sanity check.
- Original module
- No original module exists within this kernel
- Installation
- Installing to /lib/modules/4.4.0-22-generic/updates/dkms/
depmod..........
DKMS: install completed.
modprobe: ERROR: could not insert 'wl': Required key not available
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools (0.122ubuntu8) ...
update-initramfs: Generating /boot/initrd.img-4.4.0-22-generic
ifconfig：
eth0 Link encap:Ethernet HWaddr f0:76:1c:cd:b7:bd
inet addr:192.168.1.193 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::f276:1cff:fecd:b7bd/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:491801 errors:0 dropped:0 overruns:0 frame:0
TX packets:169157 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:233366815 (233.3 MB) TX bytes:22879754 (22.8 MB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:41422 errors:0 dropped:0 overruns:0 frame:0
TX packets:41422 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:3278423 (3.2 MB) TX bytes:3278423 (3.2 MB)
lspci：
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Root Complex
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kaveri [Radeon R6 Graphics]
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Kaveri HDMI/DP Audio Controller
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1424
00:02.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 1425
00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1424
00:03.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Root Port
00:03.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Root Port
00:04.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1424
00:10.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller (rev 09)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 40)
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11)
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 11)
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 11)
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 11)
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 16)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 01)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11)
00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] FCH PCI Bridge (rev 40)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 15h (Models 30h-3fh) Processor Function 5
01:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Opal XT [Radeon R7 M265]
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. Device 5287 (rev 01)
02:00.1 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 12)
03:00.0 Network controller: Broadcom Corporation BCM43142 802.11b/g/n (rev 01)
lsb_release -a：
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.04 LTS
Release: 16.04
Codename: xenial
uname -a：
Linux febriyanti-notebookif 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:46 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Why why there is an error "DKMS: install completed. modprobe: ERROR: could not insert 'wl': Required key not available update-initramfs: deferring update (trigger activated) Processing triggers for initramfs-tools (0.122ubuntu8) ... update-initramfs: Generating /boot/initrd.img-4.4.0-22-generic"?
我该怎么做才能让我的 WiFi 再次工作？