[src/trunk]: src/sys/dev/acpi Two changes:

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

details:   https://anonhg.NetBSD.org/src/rev/a9f0cd526447
branches:  trunk
changeset: 757157:a9f0cd526447
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Mon Aug 16 20:07:57 2010 +0000

description:
Two changes:

  1.    Initialize P-states properly to P0. It is processor-specific
        what value we might get without initialization. (Some AMD CPUs
        have even specific registers for the state after cold reset.)

  2.    Following design notes for Windows, set the lowest-power P-state
        upon suspend and restore the saved state after resume.

diffstat:

 sys/dev/acpi/acpi_cpu.c        |  12 +++---
 sys/dev/acpi/acpi_cpu_pstate.c |  75 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 75 insertions(+), 12 deletions(-)

diffs (190 lines):

diff -r 7dd4dbe4b6e9 -r a9f0cd526447 sys/dev/acpi/acpi_cpu.c
--- a/sys/dev/acpi/acpi_cpu.c   Mon Aug 16 19:39:06 2010 +0000
+++ b/sys/dev/acpi/acpi_cpu.c   Mon Aug 16 20:07:57 2010 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu.c,v 1.17 2010/08/16 17:58:42 jruoho Exp $ */
+/* $NetBSD: acpi_cpu.c,v 1.18 2010/08/16 20:07:57 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.c,v 1.17 2010/08/16 17:58:42 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu.c,v 1.18 2010/08/16 20:07:57 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/cpu.h>
@@ -519,8 +519,6 @@
 {
        struct acpicpu_softc *sc = device_private(self);
 
-       sc->sc_cold = true;
-
        if ((sc->sc_flags & ACPICPU_FLAG_C) != 0)
                (void)acpicpu_cstate_suspend(self);
 
@@ -530,6 +528,8 @@
        if ((sc->sc_flags & ACPICPU_FLAG_T) != 0)
                (void)acpicpu_tstate_suspend(self);
 
+       sc->sc_cold = true;
+
        return true;
 }
 
@@ -538,6 +538,8 @@
 {
        struct acpicpu_softc *sc = device_private(self);
 
+       sc->sc_cold = false;
+
        if ((sc->sc_flags & ACPICPU_FLAG_C) != 0)
                (void)acpicpu_cstate_resume(self);
 
@@ -547,8 +549,6 @@
        if ((sc->sc_flags & ACPICPU_FLAG_T) != 0)
                (void)acpicpu_tstate_resume(self);
 
-       sc->sc_cold = false;
-
        return true;
 }
 
diff -r 7dd4dbe4b6e9 -r a9f0cd526447 sys/dev/acpi/acpi_cpu_pstate.c
--- a/sys/dev/acpi/acpi_cpu_pstate.c    Mon Aug 16 19:39:06 2010 +0000
+++ b/sys/dev/acpi/acpi_cpu_pstate.c    Mon Aug 16 20:07:57 2010 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: acpi_cpu_pstate.c,v 1.24 2010/08/16 17:58:42 jruoho Exp $ */
+/* $NetBSD: acpi_cpu_pstate.c,v 1.25 2010/08/16 20:07:57 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 1.24 2010/08/16 17:58:42 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_cpu_pstate.c,v 1.25 2010/08/16 20:07:57 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/evcnt.h>
@@ -55,6 +55,8 @@
 static void             acpicpu_pstate_change(struct acpicpu_softc *);
 static void             acpicpu_pstate_bios(void);
 
+static uint32_t                 acpicpu_pstate_saved;
+
 void
 acpicpu_pstate_attach(device_t self)
 {
@@ -105,7 +107,6 @@
        (void)acpicpu_pstate_max(sc);
 
        sc->sc_flags |= ACPICPU_FLAG_P;
-       sc->sc_pstate_current = sc->sc_pstate[0].ps_freq;
 
        acpicpu_pstate_bios();
        acpicpu_pstate_attach_evcnt(sc);
@@ -225,13 +226,35 @@
 acpicpu_pstate_start(device_t self)
 {
        struct acpicpu_softc *sc = device_private(self);
+       struct acpicpu_pstate *ps;
+       uint32_t i;
        int rv;
 
        rv = acpicpu_md_pstate_start();
 
-       if (rv == 0)
-               return;
+       if (rv != 0)
+               goto fail;
+
+       /*
+        * Initialize the state to the maximum.
+        */
+       for (i = 0, rv = ENXIO; i < sc->sc_pstate_count; i++) {
+
+               ps = &sc->sc_pstate[i];
 
+               if (ps->ps_freq != 0) {
+                       sc->sc_cold = false;
+                       rv = acpicpu_pstate_set(sc, ps->ps_freq);
+                       break;
+               }
+       }
+
+       if (rv != 0)
+               goto fail;
+
+       return;
+
+fail:
        sc->sc_flags &= ~ACPICPU_FLAG_P;
        aprint_error_dev(self, "failed to start P-states (err %d)\n", rv);
 }
@@ -239,6 +262,40 @@
 bool
 acpicpu_pstate_suspend(device_t self)
 {
+       struct acpicpu_softc *sc = device_private(self);
+       struct acpicpu_pstate *ps = NULL;
+       int32_t i;
+
+       if (acpicpu_pstate_saved != 0)
+               return true;
+
+       /*
+        * Following design notes for Windows, we set the highest
+        * P-state when entering any of the system sleep states.
+        * When resuming, the saved P-state will be restored.
+        *
+        *      Microsoft Corporation: Windows Native Processor
+        *      Performance Control. Version 1.1a, November, 2002.
+        */
+       for (i = sc->sc_pstate_count - 1; i >= 0; i--) {
+
+               if (sc->sc_pstate[i].ps_freq != 0) {
+                       ps = &sc->sc_pstate[i];
+                       break;
+               }
+       }
+
+       if (__predict_false(ps == NULL))
+               return true;
+
+       mutex_enter(&sc->sc_mtx);
+       acpicpu_pstate_saved = sc->sc_pstate_current;
+       mutex_exit(&sc->sc_mtx);
+
+       if (acpicpu_pstate_saved == ps->ps_freq)
+               return true;
+
+       (void)acpicpu_pstate_set(sc, ps->ps_freq);
 
        return true;
 }
@@ -246,6 +303,12 @@
 bool
 acpicpu_pstate_resume(device_t self)
 {
+       struct acpicpu_softc *sc = device_private(self);
+
+       if (acpicpu_pstate_saved != 0) {
+               (void)acpicpu_pstate_set(sc, acpicpu_pstate_saved);
+               acpicpu_pstate_saved = 0;
+       }
 
        acpicpu_pstate_callback(self);
 
@@ -278,7 +341,7 @@
                 * If the maximum changed, proactively
                 * raise or lower the target frequency.
                 */
-               acpicpu_pstate_set(sc, sc->sc_pstate[new].ps_freq);
+               (void)acpicpu_pstate_set(sc, sc->sc_pstate[new].ps_freq);
 
 #endif
        }