i915.enable_dpcd_backlight=0
Boot parameter. In the file /etc/default/grub
add that previous code into the quotation marks after GRUB_CMDLINE_LINUX_DEFAULT=
“”
Verify to grub file:
[lnx@lnx ~]$ grep "GRUB_CMDLINE_LINUX=" /etc/default/grub
GRUB_CMDLINE_LINUX="i915.enable_dpcd_backlight=0"
Update to grub:
sudo update-grub