[src/trunk]: src/sys/dev/acpi Lower the worst-case latency in P- and T-state ...

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

details:   https://anonhg.NetBSD.org/src/rev/ab8801e9af73
branches:  trunk
changeset: 762564:ab8801e9af73
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Wed Feb 23 06:17:55 2011 +0000

description:
Lower the worst-case latency in P- and T-state transitions to 1 usec.
The previous 10 usec was based on the Intel's Core family. It may have been
improved since that. Also provide an arbitrary upper bound for BIOS bugs.

diffstat:

 sys/dev/acpi/acpi_cpu_pstate.c |  24 ++++++++----------------
 sys/dev/acpi/acpi_cpu_tstate.c |   6 +++---
 2 files changed, 11 insertions(+), 19 deletions(-)

diffs (83 lines):

diff -r 1a1f01cbd012 -r ab8801e9af73 sys/dev/acpi/acpi_cpu_pstate.c
--- a/sys/dev/acpi/acpi_cpu_pstate.c    Wed Feb 23 06:04:31 2011 +0000
+++ b/sys/dev/acpi/acpi_cpu_pstate.c    Wed Feb 23 06:17:55 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_pstate.c,v 1.37 2011/01/30 08:55:52 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_pstate.c,v 1.38 2011/02/23 06:17:55 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_pstate.c,v 1.37 2011/01/30 08:55:52 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_pstate.c,v 1.38 2011/02/23 06:17:55 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/evcnt.h>
@@ -480,12 +480,8 @@
        if (ps->ps_freq == 0 || ps->ps_freq > 9999)
                return AE_BAD_DECIMAL_CONSTANT;
 
-       /*
-        * The latency is typically around 10 usec
-        * on Intel CPUs. Use that as the minimum.
-        */
-       if (ps->ps_latency < 10)
-               ps->ps_latency = 10;
+       if (ps->ps_latency == 0 || ps->ps_latency > 1000)
+               ps->ps_latency = 1;
 
        return AE_OK;
 }
@@ -595,18 +591,14 @@
        if (ps->ps_status_mask == 0)
                ps->ps_status_mask = ACPI_GET64(elm[7].Buffer.Pointer);
 
-       /*
-        * The latency is often defined to be
-        * zero on AMD systems. Raise that to 1.
-        */
-       if (ps->ps_latency == 0)
-               ps->ps_latency = 1;
-
        ps->ps_flags |= ACPICPU_FLAG_P_XPSS;
 
-       if (ps->ps_freq > 9999)
+       if (ps->ps_freq == 0 || ps->ps_freq > 9999)
                return AE_BAD_DECIMAL_CONSTANT;
 
+       if (ps->ps_latency == 0 || ps->ps_latency > 1000)
+               ps->ps_latency = 1;
+
        return AE_OK;
 }
 
diff -r 1a1f01cbd012 -r ab8801e9af73 sys/dev/acpi/acpi_cpu_tstate.c
--- a/sys/dev/acpi/acpi_cpu_tstate.c    Wed Feb 23 06:04:31 2011 +0000
+++ b/sys/dev/acpi/acpi_cpu_tstate.c    Wed Feb 23 06:17:55 2011 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_tstate.c,v 1.20 2011/02/18 07:00:05 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_tstate.c,v 1.21 2011/02/23 06:17:55 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_tstate.c,v 1.20 2011/02/18 07:00:05 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_tstate.c,v 1.21 2011/02/23 06:17:55 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/evcnt.h>
@@ -400,7 +400,7 @@
         if (ts->ts_percent < 10 || ts->ts_percent > 100)
                return AE_BAD_DECIMAL_CONSTANT;
 
-       if (ts->ts_latency < 1)
+       if (ts->ts_latency == 0 || ts->ts_latency > 1000)
                ts->ts_latency = 1;
 
        return AE_OK;