问题现象：

root# uname -a
Linux puppypc31791 5.4.53 #1 SMP PREEMPT Sun Jul 26 12:11:02 BST 2020 x86_64 x86_64 x86_64 GNU/Linux
root# dmesg |grep -i wifi > dmesg-wifi.log
[   16.720970] Intel(R) Wireless WiFi driver for Linux
[   16.721463] iwlwifi 0000:02:00.0: enabling device (0000 -> 0002)
[   16.730542] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-50.ucode failed with error -2
[   16.730557] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-49.ucode failed with error -2
[   16.730569] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-48.ucode failed with error -2
[   16.730581] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-47.ucode failed with error -2
[   16.730593] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-46.ucode failed with error -2
[   16.730605] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-45.ucode failed with error -2
[   16.730618] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-44.ucode failed with error -2
[   16.730630] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-43.ucode failed with error -2
[   16.730642] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-42.ucode failed with error -2
[   16.730654] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-41.ucode failed with error -2
[   16.730665] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-40.ucode failed with error -2
[   16.730677] iwlwifi 0000:02:00.0: Direct firmware load for iwlwifi-cc-a0-39.ucode failed with error -2
[   16.730678] iwlwifi 0000:02:00.0: no suitable firmware found!
[   16.730679] iwlwifi 0000:02:00.0: minimum version required: iwlwifi-cc-a0-39
[   16.730679] iwlwifi 0000:02:00.0: maximum version supported: iwlwifi-cc-a0-50
[   16.730679] iwlwifi 0000:02:00.0: check git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git

处理方法：

https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
点击tree页签，这ctrl+f搜索最新驱动iwlwifi-cc-a0-50.ucode，
坑：右键另存为文件–重启进入linux发现是个html页面。
正确方法：点击iwlwifi-cc-a0-50.ucode进入页面，在blob:1aa…1de(plain)点击plain会提示下载。
把文件拷贝到U盘，启动linux后再拷贝到/lib/firmware目录，重启linux。
正常出现wifi图标，ifconfig看到wlan0网卡

日志输出更新：

root# dmesg|grep iwlwifi
[   16.482369] iwlwifi 0000:02:00.0: enabling device (0000 -> 0002)
[   16.500676] iwlwifi 0000:02:00.0: TLV_FW_FSEQ_VERSION: FSEQ Version: 58.3.35.22
[   16.500679] iwlwifi 0000:02:00.0: Found debug destination: EXTERNAL_DRAM
[   16.500680] iwlwifi 0000:02:00.0: Found debug configuration: 0
[   16.500891] iwlwifi 0000:02:00.0: loaded firmware version 50.3e391d3e.0 op_mode iwlmvm
[   16.521415] iwlwifi 0000:02:00.0: Detected Intel(R) Wi-Fi 6 AX200 160MHz, REV=0x340
[   16.534313] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM
[   16.534497] iwlwifi 0000:02:00.0: Allocated 0x00400000 bytes for firmware monitor.
[   16.722860] iwlwifi 0000:02:00.0: base HW address: 84:1b:77:xx:xx:xx
[   29.357856] iwlwifi 0000:02:00.0: Applying debug destination EXTERNAL_DRAM
[   29.540721] iwlwifi 0000:02:00.0: FW already configured (0) - re-configuring
root#