Ubuntu如何卸载cuda driver

Ubuntu上安装了cuda driver后不能启动进入界面，只好通过recovery模式进入，然后卸载cuda driver。

参考地址：

How to uninstall the NVIDIA drivers on Ubuntu 20.04 step by step instructions

https://linuxconfig.org/how-to-uninstall-the-nvidia-drivers-on-ubuntu-20-04-focal-fossa-linux

这里列出了两种方法，介绍如下，

方法一: Uninstall the Ubuntu repository and PPA NVIDIA drivers

1. The following command will remove the proprietary Nvidia driver:

   $ sudo dpkg -P $(dpkg -l | grep nvidia-driver | awk '{print $2}')
   $ sudo apt autoremove
   

2. Switch back to nouveau driver:

   $ sudo apt install xserver-xorg-video-nouveau
   

   The above switch from Nvidia to Nouveau driver can also be performed from GNOME GUI Software & Updates application window.

3. Reboot your system.
4. Once your system has rebooted confirm loaded nouveau modules:

   $ lsmod | grep nouveau
   nouveau              1949696  4
   mxm_wmi                16384  1 nouveau
   ttm                   106496  1 nouveau
   drm_kms_helper        184320  1 nouveau
   drm                   491520  7 drm_kms_helper,ttm,nouveau
   i2c_algo_bit           16384  1 nouveau
   wmi                    32768  3 wmi_bmof,mxm_wmi,nouveau
   video                  49152  1 nouveau

方法二：Uninstall the official NVIDIA drivers

For Nvidia drivers downloaded and installed from the official Nvidia website follow the below steps for Nvidia driver uninstall and to switch back to Nouveau opensource driver.

1. Locate the installation script used to install the Nvidia driver. In case you cannot locate the original installation script simply re-download it again.

   $ ls
   NVIDIA-Linux-x86_64-440.44.run
   

2. Uninstall the Nvidia Driver. Update the below Nvidia script name where appropriate :

   $ sudo bash NVIDIA-Linux-x86_64-XXX.XX.run --uninstall
   

3. If you have not done so yet, restore your xorg original configuration from backup:

   $ sudo nvidia-xconfig --restore-original-backup
   

4. Enable Nouveau modules. If you followed our guide on how to disable nouveau drivers on Ubuntu 20.04 execute the following command:

   $ sudo rm /etc/modprobe.d/blacklist-nvidia-nouveau.conf
   

5. Reboot your Ubuntu 20.04 system.