Messages in this thread | | | Date | Fri, 3 Sep 1999 13:30:04 +0200 (CEST) | From | Simon Richter <> | Subject | The future of ACPI4Linux |
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Hi,
As some of you might already know, there are now (at least :-) ) two concurrent approaches to implementing ACPI. I do not think that concurrently developing them is a good idea, and I hope you all agree on this. I will summarize the advantages and disadvantages of these solutions briefly:
The "classic" ACPI4Linux patch: This is a rather huge patchset which already does some things that do not require the AML VM to work. Its greatest strength is that it contains much useful code, its greatest weakness size and complexity. I believe that following this track will need enlarging the kernel by about 300k before we can even dare to activate any real features.
A modular approach: This is a solution that is entirely module-based as opposed to the ACPI4Linux patch which is not modularisable. It should work on 95% of all PCs without patching the kernel, and on 100% with a 2k sized patch to memory management. The current concept leaves the effective work to a userspace daemon, the module itself just registers the interrupts and reaches the events down to userspace. Its greatest strength is simplicity, its greatest weakness the fact that ACPI devices need to be initialized by an ACPI enumerator to work correctly, which would require e.g. the IDE driver to reinitialize the device while the machine is already up and running, a thing I would not like.
Both patches will require greater changes to other drivers, such as IDE and USB later on.
I, personally, would vote for the ACPI4Linux patch because testing is easier if you play with the hardware at a stage where you cannot do much damage, but other people, including Max Berger, who is the "kernel guy" of the project (I'm more into userland code) think different on this issue [Max, Andy, I think it would be good to post something more about the module here].
We need to make a decision soon, and we would like to have your opinion.
Simon
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