If the temperature is at _HOT or _CRT for 3 sequential readings, shutdown

the system.  Also, decrease the poll interval to 10 seconds from 30
seconds.  This is needed because some systems will report an invalid high
temperature for one poll cycle.  It is suspected this is due to the
embedded controller timing out.  A typical value is 138C for one cycle on a
system that is otherwise 65C.  This prevents the system from prematurely
shutting down after one invalid reading.  It will still shut down after 30
seconds of high temperature, which is the same as previous default
behavior.

Tested by:	Scott Lambert <lambert AT lambertfam.org>

1 files changed, 21 insertions, 14 deletions

diff --git a/sys/dev/acpica/acpi_thermal.c b/sys/dev/acpica/acpi_thermal.c
index 7efec65..32fb551 100644
--- a/sys/dev/acpica/acpi_thermal.c
+++ b/sys/dev/acpica/acpi_thermal.c
@@ -53,8 +53,11 @@ ACPI_MODULE_NAME("THERMAL")
 #define TZ_NOTIFY_LEVELS	0x81
 #define TZ_NOTIFY_DEVICES	0x82
 
-/* Check for temperature changes every 30 seconds by default */
-#define TZ_POLLRATE	30
+/* Check for temperature changes every 10 seconds by default */
+#define TZ_POLLRATE	10
+
+/* Make sure the reported temperature is valid for this number of polls. */
+#define TZ_VALIDCHECKS	3
 
 /* ACPI spec defines this */
 #define TZ_NUMLEVELS	10
@@ -71,7 +74,6 @@ struct acpi_tz_zone {
     int		tzp;
 };
 
-
 struct acpi_tz_softc {
     device_t			tz_dev;
     ACPI_HANDLE			tz_handle;	/*Thermal zone handle*/
@@ -95,6 +97,7 @@ struct acpi_tz_softc {
     
     struct acpi_tz_zone 	tz_zone;	/*Thermal zone parameters*/
     int				tz_tmp_updating;
+    int				tz_validchecks;
 };
 
 static int	acpi_tz_probe(device_t dev);
@@ -472,18 +475,22 @@ acpi_tz_monitor(void *Context)
     /* XXX (de)activate any passive cooling that may be required. */
 
     /*
-     * If we have just become _HOT or _CRT, warn the user.
-     *
-     * We should actually shut down at this point, but it's not clear
-     * that some systems don't actually map _CRT to the same value as _AC0.
+     * If the temperature is at _HOT or _CRT, increment our event count.
+     * If it has occurred enough times, shutdown the system.  This is
+     * needed because some systems will report an invalid high temperature
+     * for one poll cycle.  It is suspected this is due to the embedded
+     * controller timing out.  A typical value is 138C for one cycle on
+     * a system that is otherwise 65C.
      */
-    if ((newflags & (TZ_THFLAG_HOT | TZ_THFLAG_CRT)) != 0 && 
-	(sc->tz_thflags & (TZ_THFLAG_HOT | TZ_THFLAG_CRT)) == 0) {
-
-	device_printf(sc->tz_dev,
-	    "WARNING - current temperature (%d.%dC) exceeds system limits\n",
-		      TZ_KELVTOC(sc->tz_temperature));
-	shutdown_nice(RB_POWEROFF);
+    if ((newflags & (TZ_THFLAG_HOT | TZ_THFLAG_CRT)) != 0) {
+	if (++sc->tz_validchecks == TZ_VALIDCHECKS) {
+	    device_printf(sc->tz_dev,
+		"WARNING - current temperature (%d.%dC) exceeds safe limits\n",
+		TZ_KELVTOC(sc->tz_temperature));
+	    shutdown_nice(RB_POWEROFF);
+	}
+    } else {
+	sc->tz_validchecks = 0;
     }
     sc->tz_thflags = newflags;