Comment 6 for bug 1861925

I have tried the the points 1-16 in the document https://wiki.ubuntu.com/Kernel/Debugging/Backlight
but I think in the latest kernel (5.5++) some parameters are removed. https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

Point 10: use_bios_initial_backlight is not found in:
https://www.kernel.org/doc/html/latest/search.html?q=use_bios_initial_backlight&check_keywords=yes&area=default

Point 11: https://www.kernel.org/doc/html/latest/search.html?q=use_native_backlight&check_keywords=yes&area=default#

On 5.6.rc1 the parameters for vide are under: /sys/module/video/parameters/
report_key_events
only_lcd
hw_changes_brightness
disable_backlight_sysfs_if
device_id_scheme
brightness_switch_enabled
allow_duplications

The problem is I have not found any documentation to these parameters too... :(