我安装了两周的Arch Linux。作为显示管理器，我安装了 LightDM。
几天来，我在从 lightdm.service 启动系统时遇到错误，并且[电子邮件受保护]。
我只看到一个黑色显示器，必须登录另一个终端。
日志来自[电子邮件受保护]说，我没有设备 acpi_video0。
-- Reboot --
Sep 19 13:30:39 markus-pc systemd[1]: Starting Load/Save Screen Backlight Brightness of backlight:acpi_video0...
Sep 19 13:30:39 markus-pc systemd-backlight[453]: Failed to get backlight or LED device 'backlight:acpi_video0': No such device
Sep 19 13:30:39 markus-pc systemd[1]: systemd-backlight@backlight:acpi_video0.service: Main process exited, code=exited, status=1/FAILURE
Sep 19 13:30:39 markus-pc systemd[1]: Failed to start Load/Save Screen Backlight Brightness of backlight:acpi_video0.
Sep 19 13:30:39 markus-pc systemd[1]: systemd-backlight@backlight:acpi_video0.service: Unit entered failed state.
Sep 19 13:30:39 markus-pc systemd[1]: systemd-backlight@backlight:acpi_video0.service: Failed with result 'exit-code'.
Arch Linux维基页面描述每个设备都有一个目录/sys/class/backlight，但我没有。
markus@markus-pc:~$ ls -la /sys/class/backlight/
insgesamt 0
drwxr-xr-x 2 root root 0 19. Sep 13:53 .
drwxr-xr-x 51 root root 0 19. Sep 13:53 ..
当我启动桌面环境 cinnamon 并告诉[电子邮件受保护]他必须使用这张显卡来显示LightDM？
这是我的 LightDM 错误。
-- Reboot --
Sep 19 13:49:19 markus-pc systemd[1]: Starting Light Display Manager...
Sep 19 13:49:19 markus-pc systemd[1]: Started Light Display Manager.
Sep 19 13:49:37 markus-pc systemd[1]: Starting Light Display Manager...
Sep 19 13:49:37 markus-pc systemd[1]: Started Light Display Manager.
Sep 19 13:49:38 markus-pc lightdm[836]: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Main process exited, code=exited, status=1/FAILURE
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Unit entered failed state.
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Failed with result 'exit-code'.
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Service hold-off time over, scheduling restart.
Sep 19 13:49:39 markus-pc systemd[1]: Stopped Light Display Manager.
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Start request repeated too quickly.
Sep 19 13:49:39 markus-pc systemd[1]: Failed to start Light Display Manager.
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Unit entered failed state.
Sep 19 13:49:39 markus-pc systemd[1]: lightdm.service: Failed with result 'exit-code'
答案1
编辑该文件/etc/default/grub并将以下参数添加到GRUB_CMDLINE_LINUX_DEFAULT：
$ sudo nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi=Linux acpi_backlight=vendor"
别忘了sudo update-grub事后跑步。