[src/trunk]: src/sys/dev/acpi Upon request from jmcneill@, put the check back...

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

details:   https://anonhg.NetBSD.org/src/rev/3a4e41f8e10f
branches:  trunk
changeset: 760810:3a4e41f8e10f
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Thu Jan 13 13:05:13 2011 +0000

description:
Upon request from jmcneill@, put the check back that prevents unnecessary
readings during the sysmon_envsys(9) poll cycle. Some systems (notably,
Asus EeePC) have so badly implemented AML that reading the values via
envstat(8) alone can cause considerable delays.

diffstat:

 sys/dev/acpi/acpi_bat.c |  24 +++++++++++++++++++-----
 1 files changed, 19 insertions(+), 5 deletions(-)

diffs (64 lines):

diff -r a5b91410e0e2 -r 3a4e41f8e10f sys/dev/acpi/acpi_bat.c
--- a/sys/dev/acpi/acpi_bat.c   Thu Jan 13 12:55:19 2011 +0000
+++ b/sys/dev/acpi/acpi_bat.c   Thu Jan 13 13:05:13 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: acpi_bat.c,v 1.107 2011/01/09 09:47:55 jruoho Exp $    */
+/*     $NetBSD: acpi_bat.c,v 1.108 2011/01/13 13:05:13 jruoho Exp $    */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -75,7 +75,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: acpi_bat.c,v 1.107 2011/01/09 09:47:55 jruoho Exp $");
+__KERNEL_RCSID(0, "$NetBSD: acpi_bat.c,v 1.108 2011/01/13 13:05:13 jruoho Exp $");
 
 #include <sys/param.h>
 #include <sys/condvar.h>
@@ -148,6 +148,7 @@
 struct acpibat_softc {
        struct acpi_devnode     *sc_node;
        struct sysmon_envsys    *sc_sme;
+       struct timeval           sc_last;
        envsys_data_t           *sc_sensor;
        char                     sc_serial[64];
        kmutex_t                 sc_mutex;
@@ -665,6 +666,7 @@
        }
 
        sc->sc_present = rv;
+       microtime(&sc->sc_last);
 
        cv_broadcast(&sc->sc_condvar);
        mutex_exit(&sc->sc_mutex);
@@ -777,14 +779,26 @@
 static void
 acpibat_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
 {
-       device_t dv = sme->sme_cookie;
-       struct acpibat_softc *sc = device_private(dv);
+       device_t self = sme->sme_cookie;
+       struct acpibat_softc *sc;
+       struct timeval tv, tmp;
        ACPI_STATUS rv;
 
+       sc = device_private(self);
+
+       tmp.tv_sec = 10;
+       tmp.tv_usec = 0;
+
+       microtime(&tv);
+       timersub(&tv, &tmp, &tv);
+
+       if (timercmp(&tv, &sc->sc_last, <) != 0)
+               return;
+
        if (mutex_tryenter(&sc->sc_mutex) == 0)
                return;
 
-       rv = AcpiOsExecute(OSL_NOTIFY_HANDLER, acpibat_update_status, dv);
+       rv = AcpiOsExecute(OSL_NOTIFY_HANDLER, acpibat_update_status, self);
 
        if (ACPI_SUCCESS(rv))
                cv_timedwait(&sc->sc_condvar, &sc->sc_mutex, hz);