我刚买了一个新的 WiFi 棒 DMG-19，想使用它的 5Ghz 功能，因为我当前的笔记本电脑内置 WiFi 模块无法在此频率下工作。该棒可以在我朋友的 Windows 10 下工作（我在列表中看到无线网络 2，可以毫无问题地连接），但我无法在我的 Kubuntu 16.04 系统上使用它。
$lsb_release -a
没有可用的 LSB 模块。
分销商 ID：Ubuntu
描述：Ubuntu 16.04.6 LTS
版本：16.04
我的内核是 4.4.0-177-generic #207-Ubuntu SMP Mon Mar 16 01:16:10 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
盒子上的信息显示，它使用 RTL8811cu 芯片组，正如这里提到的Realtek RTL8811CU 无线上网卡 我下载了 repo 并安装了驱动程序。之后我：
$ dkms status
rtl8821CU，5.4.1，4.4.0-177-通用，x86_64：已安装
$ lsusb
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 003: ID 8087:07da Intel Corp.
Bus 001 Device 005: ID 0bda:1a2b Realtek Semiconductor Corp.
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 002: ID 174f:114f Syntek
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
设备 005 是棒。当我检查lsmod此步骤时，它没有显示 8821cu，因此我转到 /lib/modules/4.4.0-177-generic/updates/dkms 并运行sudo modprobe 8821cu目录中找到的 。然后
$ lsmod | grep 8821
8821cu 2211840 0
cfg80211 565248 4 iwlwifi,mac80211,iwldvm,8821cu
$ dmesg | grep 8821cu
[ 2296.746080] 8821cu: loading out-of-tree module taints kernel.
[ 2296.748542] 8821cu: module verification failed: signature and/or required key missing - tainting kernel
[ 2296.761367] RTW: rtl8821cu v5.4.1_28754.20180921_COEX20180712-3232
[ 2296.761372] RTW: rtl8821cu BT-Coex version = COEX20180712-3232
[ 2296.761472] usbcore: registered new interface driver rtl8821cu
$ rfkill list
0: ideapad_wlan: Wireless LAN
Soft blocked: no
Hard blocked: no
1: ideapad_bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
2: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
但在这里我没有看到它的界面
$ iwconfig
wlp3s0 IEEE 802.11bgn ESSID:"L&A"
Mode:Managed Frequency:2.472 GHz Access Point: D8:07:B6:4E:C9:93
Bit Rate=65 Mb/s Tx-Power=15 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:on
Link Quality=70/70 Signal level=-31 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:1 Invalid misc:560 Missed beacon:0
enp2s0 no wireless extensions.
lo no wireless extensions.
并
$ sudo lshw -C network显示这张图片，我也没有看到该设备：
*-network
description: Ethernet interface
product: QCA8172 Fast Ethernet
vendor: Qualcomm Atheros
physical id: 0
bus info: pci@0000:02:00.0
logical name: enp2s0
version: 10
serial: 20:1a:06:8e:68:69
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=alx latency=0 link=no multicast=yes port=twisted pair
resources: irq:32 memory:d8500000-d853ffff ioport:2000(size=128)
*-network
description: Wireless interface
product: Centrino Wireless-N 135
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlp3s0
version: c4
serial: 0c:d2:92:ae:bf:8c
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=4.4.0-177-generic firmware=18.168.6.1 ip=192.168.0.160 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
resources: irq:30 memory:d8400000-d8401fff
我做错了什么？我还尝试使用 1A2B 设备编辑一个文件，如下所述https://www.raspberrypi.org/forums/viewtopic.php?t=230499 并且还尝试了该答案中存储库中的驱动程序。