On Tue, Oct 25, 2022 at 08:50:54PM +0200, Hans de Goede wrote: > That is a valid point, but keep in mind that this is only used on ACPI > platforms and then only on devices with a builtin LCD panel and then > only by GPU drivers which actually call acpi_video_get_backlight_type(), > so e.g. not by all the ARM specific display drivers. > > So I believe that Chromebooks quite likely are the only devices with > this issue. My laptop is, uh, weird, but it falls into this category. > > I think for this to work correctly you need to have > > the infrastructure be aware of whether or not a vendor interface exists, > > which means having to handle cleanup if a vendor-specific module gets > > loaded later. > > Getting rid of the whole ping-ponging of which backlight drivers > get loaded during boot was actually one of the goals of the rework > which landed in 6.1 this actually allowed us to remove some quirks > because some hw/firmware did not like us changing our mind and > switching backlight interfaces after first poking another one. > So we definitely don't want to go back to the ping-pong thing. Defaulting to native but then having a vendor driver be able to disable native drivers seems easiest? It shouldn't be a regression over the previous state of affairs since both drivers were being loaded already.