[src/trunk]: src/sys/arch/x86/acpi Add a comment.

[jruoho <jruoho%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a8cd1cbee894
branches:  trunk
changeset: 757241:a8cd1cbee894
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Sat Aug 21 07:18:34 2010 +0000

description:
Add a comment.

diffstat:

 sys/arch/x86/acpi/acpi_cpu_md.c |  10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diffs (31 lines):

diff -r e177991b1f9f -r a8cd1cbee894 sys/arch/x86/acpi/acpi_cpu_md.c
--- a/sys/arch/x86/acpi/acpi_cpu_md.c   Sat Aug 21 06:45:50 2010 +0000
+++ b/sys/arch/x86/acpi/acpi_cpu_md.c   Sat Aug 21 07:18:34 2010 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_md.c,v 1.25 2010/08/21 06:45:50 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_md.c,v 1.26 2010/08/21 07:18:34 jruoho Exp $ */
 
 /*-
  * Copyright (c) 2010 Jukka Ruohonen <jruohonen%iki.fi@localhost>
@@ -27,7 +27,7 @@
  * SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_md.c,v 1.25 2010/08/21 06:45:50 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_md.c,v 1.26 2010/08/21 07:18:34 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -400,6 +400,12 @@
                return ENODEV;
        }
 
+       /*
+        * Fill the P-state structures with MSR addresses that are
+        * known to be correct. But only do this when the values
+        * reported by BIOS are absent. If a vendor uses XPSS, we
+        * do not necessary need to do anything to support new CPUs.
+        */
        while (i < sc->sc_pstate_count) {
 
                ps = &sc->sc_pstate[i];