LFS 11.3无法识别无线网卡并连接家庭WLAN问题求助

大家好，我最近为了深入学习Linux内部原理开始搭建LFS 11.3，但卡在无线网卡配置这一步了，甚至没法定位问题出在哪，想请大家帮忙看看。

我笔记本是Ubuntu 22和LFS 11.3双系统，Ubuntu里WLAN完全正常，所以肯定不是硬件问题。

Ubuntu 22下的正常状态 #

无线网卡硬件信息 #

执行命令 $ sudo lspci -v | grep -i "Network controller" -A 11 得到以下输出：

00:14.3 Network controller: Intel Corporation Comet Lake PCH-LP CNVi WiFi
Subsystem: Intel Corporation Wi-Fi 6 AX201 160MHz
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at d1418000 (64-bit, non-prefetchable) [size=16K]
Capabilities: [c8] Power Management version 3
Capabilities: [d0] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [40] Express Root Complex Integrated Endpoint, MSI 00
Capabilities: [80] MSI-X: Enable+ Count=16 Masked-
Capabilities: [100] Latency Tolerance Reporting
Capabilities: [164] Vendor Specific Information: ID=0010 Rev=0 Len=014 <?>
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi

可以看到无线网卡是Intel AX201，使用iwlwifi驱动。

网络接口状态 #

执行 $ ip link 能看到正常识别的无线接口wlp0s20f3：

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp4s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000
link/ether 00:2b:67:21:eb:fe brd ff:ff:ff:ff:ff:ff
3: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DORMANT group default qlen 1000
link/ether 40:ec:99:1f:d7:f4 brd ff:ff:ff:ff:ff:ff

无线设备状态文件信息 #

执行 $ sudo cat /proc/net/wireless 能看到无线设备的运行状态：

Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 22
wlp0s20f3: 0000   67.  -43.  -256        0      0      0      0    198

LFS 11.3下的异常状态 #

网络接口状态 #

执行 $ ip link 完全看不到无线接口：

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp4s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:2b:67:21:eb:fe brd ff:ff:ff:ff:ff:ff
3: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/sit 0.0.0.0 brd 0.0.0.0

无线设备状态文件信息 #

执行 $ cat /proc/net/wireless 里没有任何无线设备记录：

Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 22

内核模块对比 #

对比Ubuntu和LFS的lsmod输出，我发现LFS里缺少了cfg80211模块：

• Ubuntu下执行 $ lsmod | grep iwlwifi：

iwlwifi               503808  1 iwlmvm
cfg80211             1052672  3 iwlmvm,iwlwifi,mac80211

• LFS下执行 $ lsmod：

Module                  Size  Used by
x86_pkg_temp_thermal    20480  0
iwlwifi               454656  0

让我困惑的是，我编译LFS内核的时候已经开启了以下无线相关选项（就是为了安装wpa_supplicant-2.10）：

[*] Networking support  --->                              [CONFIG_NET]
[*] Wireless  --->                                      [CONFIG_WIRELESS]
<*/M> cfg80211 - wireless configuration API           [CONFIG_CFG80211]
[*]     cfg80211 wireless extensions compatibility    [CONFIG_CFG80211_WEXT]
<*/M> Generic IEEE 802.11 Networking Stack (mac80211) [CONFIG_MAC80211]
Device Drivers  --->
[*] Network device support  --->                        [CONFIG_NETDEVICES]
[*] Wireless LAN  --->                                [CONFIG_WLAN]

麻烦大家帮忙分析下问题出在哪，谢谢了！

备注：内容来源于stack exchange，提问作者Amit