It is called unit testing. You test the backlight all by itself, without initializing the graphics subsystem. You also have coverage metrics that identify all of the input states that can affect the backlight, including any that initializing the gpu may modify, and you test the backlight code against each possible set of inputs: both if the gpu had initialized already, and if it had not.
Properly validating software is possible, but it takes a lot more work than just seeing if Windows boots up on it.
Power management, mobile and firmware developer on Linux. Security developer at Aurora. Ex-biologist. mjg59 on Twitter. Content here should not be interpreted as the opinion of my employer. Also on Mastodon.
Re: ACPI spec
Date: 2014-11-19 09:12 pm (UTC)Properly validating software is possible, but it takes a lot more work than just seeing if Windows boots up on it.