On 六, 2012-09-01 at 17:21 +0530, Durgadoss R wrote:
> This patch creates a structure to hold platform
> thermal governor information, and provides APIs
> for individual thermal governors to register/unregister
> with the Thermal framework.
>
> Signed-off-by: Durgadoss R <durgadoss.r@xxxxxxxxx>
> ---
> drivers/thermal/thermal_sys.c | 90 +++++++++++++++++++++++++++++++++++++++++
> include/linux/thermal.h | 16 ++++++++
> 2 files changed, 106 insertions(+)
>
> diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
> index a642d1c..541da47 100644
> --- a/drivers/thermal/thermal_sys.c
> +++ b/drivers/thermal/thermal_sys.c
> @@ -49,7 +49,86 @@ static DEFINE_MUTEX(thermal_idr_lock);
>
> static LIST_HEAD(thermal_tz_list);
> static LIST_HEAD(thermal_cdev_list);
> +static LIST_HEAD(thermal_governor_list);
> +
> static DEFINE_MUTEX(thermal_list_lock);
> +static DEFINE_MUTEX(thermal_governor_lock);
> +
> +static struct thermal_governor *__find_governor(const char *name)
> +{
> + struct thermal_governor *pos;
> +
> + list_for_each_entry(pos, &thermal_governor_list, governor_list)
> + if (!strnicmp(name, pos->name, THERMAL_NAME_LENGTH))
> + return pos;
> +
I'm wondering if we should return NULL here or not.
because you are invoking tz->governor->throttle() without any checking.
if there is no matched governor, fall back to the default one instead.
> + return NULL;
> +}
> +
> +int thermal_register_governor(struct thermal_governor *governor)
> +{
> + int err;
> + const char *name;
> + struct thermal_zone_device *pos;
> +
> + if (!governor)
> + return -EINVAL;
> +
> + mutex_lock(&thermal_governor_lock);
> +
> + err = -EBUSY;
> + if (__find_governor(governor->name) == NULL) {
> + err = 0;
> + list_add(&governor->governor_list, &thermal_governor_list);
> + }
> +
> + mutex_lock(&thermal_list_lock);
> +
> + list_for_each_entry(pos, &thermal_tz_list, node) {
> + if (pos->governor)
> + continue;
> + if (pos->tzp)
> + name = pos->tzp->governor_name;
> + else
> + name = DEFAULT_THERMAL_GOVERNOR;
> + if (!strnicmp(name, governor->name, THERMAL_NAME_LENGTH))
> + pos->governor = governor;
> + }
> +
> + mutex_unlock(&thermal_list_lock);
> + mutex_unlock(&thermal_governor_lock);
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(thermal_register_governor);
> +
> +void thermal_unregister_governor(struct thermal_governor *governor)
> +{
> + struct thermal_zone_device *pos;
> +
> + if (!governor)
> + return;
> +
> + mutex_lock(&thermal_governor_lock);
> +
> + if (__find_governor(governor->name) == NULL)
> + goto exit;
> +
> + mutex_lock(&thermal_list_lock);
> +
> + list_for_each_entry(pos, &thermal_tz_list, node) {
> + if (!strnicmp(pos->governor->name, governor->name,
> + THERMAL_NAME_LENGTH))
> + pos->governor = NULL;
> + }
> +
> + mutex_unlock(&thermal_list_lock);
> + list_del(&governor->governor_list);
> +exit:
> + mutex_unlock(&thermal_governor_lock);
> + return;
> +}
> +EXPORT_SYMBOL_GPL(thermal_unregister_governor);
>
> static int get_idr(struct idr *idr, struct mutex *lock, int *id)
> {
> @@ -1439,6 +1518,16 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
> if (result)
> goto unregister;
>
> + /* Update 'this' zone's governor information */
> + mutex_lock(&thermal_governor_lock);
> +
> + if (tz->tzp)
what if tzp->governor_name is not set, usually this mean the platform
driver wants to use the default governor.
so the code should be
if (tz->tzp && tz->tzp->governor_name[0])
thanks,
rui
> + tz->governor = __find_governor(tz->tzp->governor_name);
> + else
> + tz->governor = __find_governor(DEFAULT_THERMAL_GOVERNOR);
> +
> + mutex_unlock(&thermal_governor_lock);
> +
> result = thermal_add_hwmon_sysfs(tz);
> if (result)
> goto unregister;
> @@ -1502,6 +1591,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
> if (tz->ops->get_mode)
> device_remove_file(&tz->device, &dev_attr_mode);
> remove_trip_attrs(tz);
> + tz->governor = NULL;
>
> thermal_remove_hwmon_sysfs(tz);
> release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> index 58cb1c0..6182bd5 100644
> --- a/include/linux/thermal.h
> +++ b/include/linux/thermal.h
> @@ -46,6 +46,9 @@
> #define THERMAL_GENL_VERSION 0x01
> #define THERMAL_GENL_MCAST_GROUP_NAME "thermal_mc_group"
>
> +/* Default Thermal Governor: Does Linear Throttling */
> +#define DEFAULT_THERMAL_GOVERNOR "step_wise"
> +
> struct thermal_zone_device;
> struct thermal_cooling_device;
>
> @@ -158,6 +161,7 @@ struct thermal_zone_device {
> unsigned int forced_passive;
> const struct thermal_zone_device_ops *ops;
> const struct thermal_zone_params *tzp;
> + struct thermal_governor *governor;
> struct list_head thermal_instances;
> struct idr idr;
> struct mutex lock; /* protect thermal_instances list */
> @@ -165,6 +169,14 @@ struct thermal_zone_device {
> struct delayed_work poll_queue;
> };
>
> +/* Structure that holds thermal governor information */
> +struct thermal_governor {
> + char name[THERMAL_NAME_LENGTH];
> + int (*throttle)(struct thermal_zone_device *tz, int trip);
> + struct list_head governor_list;
> + struct module *owner;
> +};
> +
> /* Structure that holds binding parameters for a zone */
> struct thermal_bind_params {
> struct thermal_cooling_device *cdev;
> @@ -189,6 +201,7 @@ struct thermal_bind_params {
>
> /* Structure to define Thermal Zone parameters */
> struct thermal_zone_params {
> + char governor_name[THERMAL_NAME_LENGTH];
> int num_tbps; /* Number of tbp entries */
> struct thermal_bind_params *tbp;
> };
> @@ -219,6 +232,9 @@ int get_tz_trend(struct thermal_zone_device *, int);
> struct thermal_instance *get_thermal_instance(struct thermal_zone_device *,
> struct thermal_cooling_device *, int);
>
> +int thermal_register_governor(struct thermal_governor *);
> +void thermal_unregister_governor(struct thermal_governor *);
> +
> #ifdef CONFIG_NET
> extern int thermal_generate_netlink_event(u32 orig, enum events event);
> #else
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