On 3/16/22 13:25, Limonciello, Mario wrote:
[Public] I guess when we see backlight issues on these A+N designs the checks should be: 1) Are they supposed to be using the nvidia-wmi-ec-backlight driver? 2) Is their kernel new enough to have it? 3) Do they have the config enabled? Do you have a script or could you perhaps include some documentation we can point people to check "1" so we don't always have to go tear apart ACPI tables and make guesses? I guess it's something like grab _WDG and then parse it to see if there is an entry.
Probably the most foolproof way would be to check for the GUID 603E9613-EF25-4338-A3D0-C46177516DB7 in /sys/bus/wmi/devices. (2) should be true for vanilla 5.16 and later, and many recent pre-5.16 distro kernels with HWE backports.
