Garrett: Why ACPI?

Matthew Garrett explainswhy ACPI exists and why it is not as bad a thing as some think.

There's an alternative universe where we decided to teach thekernel about every piece of hardware it should run on. Fortunately(or, well, unfortunately) we've seen that in the ARM world. Mostdevice-specific simply never reaches mainline, and most users arestuck running ancient kernels as a result. Imagine every x86 devicevendor shipping their own kernel optimised for their hardware, andnow imagine how well that works out given the quality of theirfirmware. Does that really seem better to you?