ubuntu22.04识别CH340的问题汇总

本文介绍: 汇总

自己的电脑装的是双系统，ubuntu22.04安装了很久好久没有（WSL2确实解决了频繁依赖 linux的问题）。昨天尝试搞一下STM32MP135的系统搭建，开始启用ubuntu22.04。但是遇到了很多问题，其中一个问题就是CH340的驱动。
在折腾的过程中遇到了多个问题，这里一并汇总。为了尊重原创者的成果，我这里将两篇博文的原始文章连接粘贴如下：
小言W的：串口驱动签名问题解决方案
 鱼香ROS的：驱动被占用问题解决方案

使用 ls usb 命令，发现发现了WCH的设备觉得应该没什么问题了。

Bus 001 Device 013: ID 1a86:7523 QinHeng Electronics CH340 serial converter

实际上查看用ls /dev/tty*却看不到新增的设备。
所以我判断是没有CH340的驱动，就去官网下载驱动:CH341SER_LINUX.ZIP .然后按照readme的教程 make，然后 make install.但是最后还是没有成功。

所以就尝试用sudo dmesg查看新插入的设备。（故意插拔了一次，所以生成的信息在最后。）结果提示:

[  820.295049] usb 1-6.2: USB disconnect, device number 9
[  822.334672] usb 1-6.3: new full-speed USB device number 10 using xhci_hcd
[  822.460652] usb 1-6.3: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[  822.460664] usb 1-6.3: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  822.460668] usb 1-6.3: Product: USB Serial
[  822.480251] Loading of unsigned module is rejected
[  823.034128] input: BRLTTY 6.4 Linux Screen Driver Keyboard as /devices/virtual/input/input45

提示未签名的模块被拒绝（Loa ding of unsigned mod ule is rejecte d）。

@小言W的文章提供了很详尽的问题怎么解决的描述。归纳如下：

sudo apt install mokutil
sudo apt install shim-signed

# 生成新签名，参考https://wiki-ubuntu-com.translate.goog/UEFI/SecureBoot?_x_tr_sl=auto&amp;_x_tr_tl=zh-CN&amp;_x_tr_hl=en-US&amp;_x_tr_pto=wapp
sudo update-secureboot-policy --new-key

# 生成密钥，参考https://wiki-ubuntu-com.translate.goog/UEFI/SecureBoot/KeyManagement/KeyGeneration?_x_tr_sl=auto&amp;_x_tr_tl=zh-CN&amp;_x_tr_hl=en-US&amp;_x_tr_pto=wapp
openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=Descriptive name/"

#导入签名
sudo mokutil --import /var/lib/shim-signed/mok/MOK.der

sudo /usr/src/linux-headers-$(uname -r)/scripts/sign-file sha256 /var/lib/shim-signed/mok/MOK.priv /var/lib/shim-signed/mok/MOK.der ch341.ko

# 检查以下驱动十分签名成功
hexdump -C ch341.ko | tail

# 若成功会有Module signature appended字样

sudo make load
sudo make install

# 检查模块load情况
lsmod | grep ch34

继续使用dmesg命令查看如果出现类似问题：

interface 0 claimed by ch341 while 'brltty' sets config #1

sudo apt remove brltty

With one exception, this document applies to using BRLTTY with any braille device. The exception is that, when key bindings are given, it assumes that the braille device has a braille keyboard. If it doesn't, then, as mentioned above, you can look up your device's corresponding key bindings online.