[PATCH] Thermal: thermal zone governor fix

Zhang Rui
2014-02-27T06:41:20Z

>From cd587add3043ed7bf3347e5d956f65ec8adf04cf Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@intel.com>
Date: Fri, 24 Jan 2014 10:23:19 +0800
Subject: [PATCH] Thermal: thermal zone governor fix

This patch does a cleanup about the thermal zone governor,
and make the following rules,
1. For thermal zone devices that are registered w/o tz->tzp,
they can use the default thermal governor only.
2. For thermal zone devices w/ governor name specified in
tz->tzp->governor_name, we will use the default governor
if the governor specified is not available at the moment,
and update tz->governor when the matched governor is registered.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
drivers/thermal/thermal_core.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/thermal/thermal_core.c
b/drivers/thermal/thermal_core.c
index 338a88b..6bcf0628a 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -56,10 +56,15 @@ static LIST_HEAD(thermal_governor_list);
static DEFINE_MUTEX(thermal_list_lock);
static DEFINE_MUTEX(thermal_governor_lock);

+static struct thermal_governor *def_governor;
+
static struct thermal_governor *__find_governor(const char *name)
{
struct thermal_governor *pos;

+ if (!name)
+ return def_governor;
+
list_for_each_entry(pos, &thermal_governor_list, governor_list)
if (!strnicmp(name, pos->name, THERMAL_NAME_LENGTH))
return pos;
@@ -82,17 +87,23 @@ int thermal_register_governor(struct
thermal_governor *governor)
if (__find_governor(governor->name) == NULL) {
err = 0;
list_add(&governor->governor_list, &thermal_governor_list);
+ if (!def_governor && !strncmp(governor->name,
+ THERMAL_DEFAULT_GOVERNOR, THERMAL_NAME_LENGTH))
+ def_governor = governor;
}

mutex_lock(&thermal_list_lock);

list_for_each_entry(pos, &thermal_tz_list, node) {
+ /*
+ * only thermal zones with specified tz->tzp->governor_name
+ * may run with tz->govenor unset
+ */
if (pos->governor)
continue;
- if (pos->tzp)
- name = pos->tzp->governor_name;
- else
- name = DEFAULT_THERMAL_GOVERNOR;
+
+ name = pos->tzp->governor_name;
+
if (!strnicmp(name, governor->name, THERMAL_NAME_LENGTH))
pos->governor = governor;
}
@@ -342,8 +353,8 @@ static void monitor_thermal_zone(struct
thermal_zone_device *tz)
static void handle_non_critical_trips(struct thermal_zone_device *tz,
int trip, enum thermal_trip_type trip_type)
{
- if (tz->governor)
- tz->governor->throttle(tz, trip);
+ tz->governor ?
+ tz->governor->throttle(tz, trip) : def_governor(tz, trip);
}

static void handle_critical_trips(struct thermal_zone_device *tz,
@@ -1533,7 +1544,7 @@ struct thermal_zone_device
*thermal_zone_device_register(const char *type,