우분투 20.04에 인텔 wifi AX211 드라이버 설치

새로 구입한 노트북에 인텔의 최신 WI-FI 6E AX211 와이파이가 설치되어 있다.

그런데 우분투 20.04에서 인식되지 않는다.

$ lspci -nnk | grep 0280 -A3
0000:00:14.3 Network controller [0280]: Intel Corporation Device [8086:51f0] (rev 01)
    DeviceName: Onboard - Ethernet
    Subsystem: Intel Corporation Device [8086:0094]
    Kernel modules: iwlwifi

lshw 에서 UNCLAIMED 라고 뜬다.

$ sudo lshw -C network
[sudo] password for khyou: 
  *-network UNCLAIMED       
       description: Network controller
       product: Intel Corporation
       vendor: Intel Corporation
       physical id: 14.3
       bus info: pci@0000:00:14.3
       version: 01
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix cap_list
       configuration: latency=0
       resources: iomemory:620-61f memory:622f284000-622f287fff
  *-network
       description: Ethernet interface
       product: RTL8125 2.5GbE Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:2c:00.0
       logical name: enp44s0
       version: 05
       serial: 50:eb:f6:d1:4b:1d
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=5.13.0-39-generic firmware=rtl8125b-2_0.0.2 07/13/20 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:18 ioport:3000(size=256) memory:60200000-6020ffff memory:60210000-60213fff

해당 드라이버를 설치하려면 인텔에서 배포하는 최신의 dkms를 적용해야하는데 

https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi 의 지원 목록에 따르면 AX211 모델은 커널 버전 5.14에 적용되므로 커널 버전 5.13인 20.04 버전에서는 설치되지 않는다고 한다.

$ uname -r
5.13.0-40-generic

해결 방법은 아래 링크에서

http://archive.ubuntu.com/ubuntu/pool/universe/b/backport-iwlwifi-dkms/

Index of /ubuntu/pool/universe/b/backport-iwlwifi-dkms

가장 최신의 backport-iwlwifi-dkms_9858-0ubuntu2_all.deb 또는 유사한 파일을 다운로드 한 다음

다음 명령어로 설치한다.

$ sudo dpkg -i backport-iwlwifi-dkms_9858-0ubuntu2_all.deb

만약 아래와 같은 에러가 발생하는 경우

Selecting previously unselected package backport-iwlwifi-dkms.
(Reading database ... 178822 files and directories currently installed.)
Preparing to unpack backport-iwlwifi-dkms_9858-0ubuntu6_all.deb ...
Unpacking backport-iwlwifi-dkms (9858-0ubuntu6) ...
dpkg: dependency problems prevent configuration of backport-iwlwifi-dkms:
 backport-iwlwifi-dkms depends on dkms (>= 2.1.0.0); however:
  Package dkms is not installed.
 backport-iwlwifi-dkms depends on libc6-dev | libc-dev; however:
  Package libc6-dev is not installed.
  Package libc-dev is not installed.

dpkg: error processing package backport-iwlwifi-dkms (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 backport-iwlwifi-dkms

문제 해결을 위해 dkms, libc6-dev를 설치하려고 하면 다른 에러가 나타난다.

$ sudo apt install dkms libc6-dev libc-dev-bin 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 dkms : Depends: gcc but it is not going to be installed or
                 c-compiler
        Depends: dpkg-dev but it is not going to be installed
        Depends: make or
                 build-essential but it is not going to be installed
        Depends: dctrl-tools
        Recommends: fakeroot
 libc6-dev : Depends: linux-libc-dev but it is not going to be installed
             Depends: libcrypt-dev but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

해결 방법은 터미널에 아래와 같이 입력하는 것.

$ sudo apt --fix-broken install

그리고나서 다시 dpkg -i 명령으로 설치하면 된다.

이제 리부팅 하면 정상적으로 인식한다.