> 1. There must be a GPU driver for these laptops somewhere? > Even if out of tree using a laptop without a GPU these days > just does not give a good user experience. So fix the GPU > driver to call acpi_video_register_backlight(). > > Note acpi_video_register_backlight() is deliberately exported > without requiring the consuming out of tree kernel module to > be GPL to allow this. > > Other options would be: > > 2. Add some special heuristics for Zhaoxin CPUs, > the kernel already has a CPUID match mechanism for > things like this. This could potentially be combined > with a DMI system-vendor check to only do this special > case handling on e.g. Lenovo and Inspur laptops. > > 3. Instead of adding the CPU-id based special case > just outright use DMI quirks. In this case lets try > to use substring matches to cover multiple models > with a single entry so as to not grow the quirk > table too much. Got it, thanks! In fact, we have tried a few approaches (cmdline option, CPU-ID based quirk, and DMI quirk), and all of them work. I will sync this information with Zhaoxin to see which way they prefer.
