On Sat, 23 Nov 2013 16:38:54 +0000, Matthew Garrett mjg59@srcf.ucam.org wrote:
On Fri, Nov 22, 2013 at 05:05:48PM -0700, Al Stone wrote:
For reduced hardware mode, however, I have to rely on the underlying ACPICA reference implementation to behave properly. Right now, ACPICA relies on compile time changes to implement either reduced HW mode or legacy mode so I have to follow suit. When I looked at making ACPICA change behavior at runtime, the changes became more and more invasive. Since x86/ia64 depend on ACPICA to behave also, that seemed a far more dangerous approach to me.
Ugh. Really? People have been fairly careful about making sure that the x86 SoC code is selected correctly at runtime, and losing that because ACPICA is broken would be a shame. I think this is something that needs to support runtime switching even if there's also support for building kernels that only implement the reduced hardware profile.
Yeah, that is a really big problem. At the very least push the hacks back into ACPICA and make that project sort it out (add stub functions if needed). I don't like seeing the kernel having #ifdef blocks to stub out normal ACPI paths.
g.