[src/trunk]: src/sys/arch/x86/acpi Add couple of comments.

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

details:   https://anonhg.NetBSD.org/src/rev/6291c5fdd920
branches:  trunk
changeset: 762684:6291c5fdd920
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Fri Feb 25 17:07:30 2011 +0000

description:
Add couple of comments.

diffstat:

 sys/arch/x86/acpi/acpi_cpu_md.c |  11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diffs (39 lines):

diff -r cdd3636416bc -r 6291c5fdd920 sys/arch/x86/acpi/acpi_cpu_md.c
--- a/sys/arch/x86/acpi/acpi_cpu_md.c   Fri Feb 25 16:54:36 2011 +0000
+++ b/sys/arch/x86/acpi/acpi_cpu_md.c   Fri Feb 25 17:07:30 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_md.c,v 1.44 2011/02/25 16:54:36 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_md.c,v 1.45 2011/02/25 17:07:30 jruoho Exp $ */
 
 /*-
  * Copyright (c) 2010, 2011 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 1.44 2011/02/25 16:54:36 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_md.c,v 1.45 2011/02/25 17:07:30 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -274,6 +274,10 @@
 
                case 0x0f:
 
+                       /*
+                        * Evaluate support for the "FID/VID
+                        * algorithm" also used by powernow(4).
+                        */
                        if ((regs[3] & CPUID_APM_FID) == 0)
                                break;
 
@@ -370,6 +374,9 @@
        bool ipi = false;
        int i;
 
+       /*
+        * Save the cpu_idle(9) loop used by default.
+        */
        x86_cpu_idle_get(&native_idle, native_idle_text, size);
 
        for (i = 0; i < ACPI_C_STATE_COUNT; i++) {