Re: Options depending on STANDALONE

From: Eric Piel
Date: Mon Aug 07 2006 - 15:12:17 EST


08/07/2006 07:33 PM, Thomas Renninger wrote/a Ãcrit:

There are three reasons for the initrd patch (last one also applies for
the compile in functionality):
Hi, I just happen to be the maintainer "this initrd patch" ;-) I agree with you Thomas. IMHO, this patch is really useful in our "not so perfect" world. Few more comments below:


1)
There might be "BIOS bugs" that will never get fixed:
https://bugzilla.novell.com/show_bug.cgi?id=160671
(Because it's an obvious BIOS bug, "compatibility" fixing it could make
things worse).
This is really feature #1, PC manufacturers come to sometimes extremely ugly things when they code their ACPI tables. You can find lots of BIOS containing in their ACPI tables tests like "do this if OS name is 13 letters long, and that if OS name is 11 letters long..." Obviously Linux is most of the time not within those tests!

1.5) Feature adding. Some (crazy?) people are working on new implementation of their ACPI table to add features (cf the "Smart Battery System for Linux" project).

In those two cases, you really can't expect every user to recompile it's Linux kernel to get an new DSDT table :-)

2)
There might be "ACPICA/kernel bugs" that take a while until they get
fixed:

This happens often. There comes out a new machine, using AML in a
slightly other way, we need to fix it in kernel/ACPICA. Until the patch
appears mainline may take a month or two. Until the distro of your
choice that makes use of the fix comes out might take half a year or
more...
And backporting ACPICA fixes to older kernels is currently not possible
as ACPICA patches appear in a big bunch of some thousand lines patches.
But this hopefully changes soon.

In my mind come:
- alias broken in certain cases
https://bugziall.novell.com/show_bug.cgi?id=113099
- recon amount of elements in packages
https://bugzilla.novell.com/show_bug.cgi?id=189488
- wrong offsets at Field and Operation Region declarations
-> should be compatible for quite a while now
- ...
Agree, although I believe of this as more an excuse than a reason. Linux is still full of bugs, lots of which cannot be fixed by ACPI table swapping anyway...

3)
Debugging.
This is why at least compile in or via initrd must be provided in
mainline kernel IMHO. Intel people themselves ask the bug reporter to
override ACPI tables with a patched table to debug the system.
Do you really think ripping out all overriding functionality from the
kernel is a good idea?
Well, I think even Len agree with this usage :-)

All in all, I'm really _not_ asking for inclusion of the patch in the main tree. Just asking you not to think too much bad of the distros which use this patch ;-) (IIRC, at least Mandriva and Ubuntu include it in addition to SuSE)

See you,
Eric

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/