Thermal: Ignore invalid trip points

In some cases, platform thermal driver may report invalid trip points,
thermal core should not take any action for these trip points.

This fixed a regression that bogus trip point starts to screw up thermal
control on some Lenovo laptops, after
commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461
Author: Zhang Rui <rui.zhang@intel.com>
Date:   Fri Oct 30 16:31:47 2015 +0800

    Thermal: initialize thermal zone device correctly

    After thermal zone device registered, as we have not read any
    temperature before, thus tz->temperature should not be 0,
    which actually means 0C, and thermal trend is not available.
    In this case, we need specially handling for the first
    thermal_zone_device_update().

    Both thermal core framework and step_wise governor is
    enhanced to handle this. And since the step_wise governor
    is the only one that uses trends, so it's the only thermal
    governor that needs to be updated.

    Tested-by: Manuel Krause <manuelkrause@netscape.net>
    Tested-by: szegad <szegadlo@poczta.onet.pl>
    Tested-by: prash <prash.n.rao@gmail.com>
    Tested-by: amish <ammdispose-arch@yahoo.com>
    Tested-by: Matthias <morpheusxyz123@yahoo.de>
    Reviewed-by: Javi Merino <javi.merino@arm.com>
    Signed-off-by: Zhang Rui <rui.zhang@intel.com>
    Signed-off-by: Chen Yu <yu.c.chen@intel.com>
CC: <stable@vger.kernel.org> #3.18+
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1317190
Link: https://bugzilla.kernel.org/show_bug.cgi?id=114551
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index a0a8fd1235e2a21cbe5553c440b26eafecf8042e..d4b54653ecf8d7f489a6200a8491b46b52f3ba14 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -454,6 +454,10 @@ static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 {
        enum thermal_trip_type type;
 
+       /* Ignore disabled trip points */
+       if (test_bit(trip, &tz->trips_disabled))
+               return;
+
        tz->ops->get_trip_type(tz, trip, &type);
 
        if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
@@ -1800,6 +1804,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 {
        struct thermal_zone_device *tz;
        enum thermal_trip_type trip_type;
+       int trip_temp;
        int result;
        int count;
        int passive = 0;
@@ -1871,9 +1876,15 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
                goto unregister;
 
        for (count = 0; count < trips; count++) {
-               tz->ops->get_trip_type(tz, count, &trip_type);
+               if (tz->ops->get_trip_type(tz, count, &trip_type))
+                       set_bit(count, &tz->trips_disabled);
                if (trip_type == THERMAL_TRIP_PASSIVE)
                        passive = 1;
+               if (tz->ops->get_trip_temp(tz, count, &trip_temp))
+                       set_bit(count, &tz->trips_disabled);
+               /* Check for bogus trip points */
+               if (trip_temp == 0)
+                       set_bit(count, &tz->trips_disabled);
        }
 
        if (!passive) {

diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 9c481991fdc7ea602bce3ccdb5b5d99d9bb2a781..a55d0523f75d63bfbe43355a56dd0f08e835cdc9 100644 (file)
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -156,6 +156,7 @@ struct thermal_attr {
  * @trip_hyst_attrs:   attributes for trip points for sysfs: trip hysteresis
  * @devdata:   private pointer for device private data
  * @trips:     number of trip points the thermal zone supports
+ * @trips_disabled;    bitmap for disabled trips
  * @passive_delay:     number of milliseconds to wait between polls when
  *                     performing passive cooling.
  * @polling_delay:     number of milliseconds to wait between polls when
@@ -191,6 +192,7 @@ struct thermal_zone_device {
        struct thermal_attr *trip_hyst_attrs;
        void *devdata;
        int trips;
+       unsigned long trips_disabled;   /* bitmap for disabled trips */
        int passive_delay;
        int polling_delay;
        int temperature;