On 17-01-2014 04:22, Zhang Rui wrote: > On Mon, 2014-01-13 at 19:17 +0800, Wei Ni wrote: >> In the of-thermal driver, it register a thermal zone device >> without governor, since the governers are not static, we >> should be able to update to a new one in run-time, so I add >> a new fucntion thermal_update_governor() to do it. >> >> In the future, the governor will be more complex, it may want >> to tune governor-specific parameters/configuration for >> different thermal zone at different run-time, so I add >> start/stop for the governor and add governor_data as governor's >> parameters, so that the thermal platform driver can change >> the governor with start/stop, and tune the governor parameters >> in run-time. > > are you going to introduce a new governor with .start/.stop implemented > or are you going to introduce .start/.stop callbacks for the current > governors?
This is what I have been questioning. > > I'd like to see if there is any real request for this. ditto. I am for introducing these APIs when the real user of them appears, say the new governor or the changes in the existing ones. >> >> Signed-off-by: Wei Ni <[email protected]> >> --- >> Documentation/thermal/sysfs-api.txt | 5 +++ >> drivers/thermal/thermal_core.c | 80 >> +++++++++++++++++++++++++++++++---- >> include/linux/thermal.h | 12 ++++++ >> 3 files changed, 88 insertions(+), 9 deletions(-) >> >> diff --git a/Documentation/thermal/sysfs-api.txt >> b/Documentation/thermal/sysfs-api.txt >> index 6a70b55c..7efd8e6 100644 >> --- a/Documentation/thermal/sysfs-api.txt >> +++ b/Documentation/thermal/sysfs-api.txt >> @@ -405,3 +405,8 @@ platform data is provided, this uses the step_wise >> throttling policy. >> This function serves as an arbitrator to set the state of a cooling >> device. It sets the cooling device to the deepest cooling state if >> possible. >> + >> +5.5:thermal_update_governor: >> +This function update the thermal zone's governor to a new one and update >> +the governor data of the new governor for that thermal zone. Returns 0 if >> +success, an erro code otherwise. >> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c >> index aab1df8..d922baf 100644 >> --- a/drivers/thermal/thermal_core.c >> +++ b/drivers/thermal/thermal_core.c >> @@ -93,10 +93,17 @@ int thermal_register_governor(struct thermal_governor >> *governor) >> name = pos->tzp->governor_name; >> else >> name = DEFAULT_THERMAL_GOVERNOR; >> - if (!strnicmp(name, governor->name, THERMAL_NAME_LENGTH)) >> + if (!strnicmp(name, governor->name, THERMAL_NAME_LENGTH)) { >> + if (governor->start) { >> + err = governor->start(pos); >> + if (err < 0) >> + goto exit; >> + } >> pos->governor = governor; >> + } >> } >> >> +exit: >> mutex_unlock(&thermal_list_lock); >> mutex_unlock(&thermal_governor_lock); >> >> @@ -119,8 +126,11 @@ void thermal_unregister_governor(struct >> thermal_governor *governor) >> >> list_for_each_entry(pos, &thermal_tz_list, node) { >> if (!strnicmp(pos->governor->name, governor->name, >> - THERMAL_NAME_LENGTH)) >> + THERMAL_NAME_LENGTH)) { >> + if (pos->governor->stop) >> + pos->governor->stop(pos); >> pos->governor = NULL; >> + } >> } >> >> mutex_unlock(&thermal_list_lock); >> @@ -130,6 +140,51 @@ exit: >> return; >> } >> >> +/** >> + * thermal_update_governor() - update the thermal zone device's governor >> + * to a new one. >> + * @tzd: pointer of thermal zone device, which need to update governor. >> + * @name: new governor name. >> + * @gov_data: governor data for the new governor if needed. >> + * >> + * Return: On success returns 0, an error code otherwise >> + */ >> +int thermal_update_governor(struct thermal_zone_device *tzd, >> + const char *name, void *gov_data) >> +{ >> + struct thermal_governor *old_gov, *new_gov; >> + int ret = 0; >> + >> + mutex_lock(&thermal_governor_lock); >> + >> + new_gov = __find_governor(name); >> + if (!new_gov) { >> + ret = -EINVAL; >> + goto exit; >> + } >> + >> + old_gov = tzd->governor; >> + >> + if (old_gov && old_gov->stop) >> + old_gov->stop(tzd); >> + >> + if (new_gov->start) { >> + ret = new_gov->start(tzd); >> + if (ret < 0) { >> + if (old_gov && old_gov->start) >> + old_gov->start(tzd); >> + goto exit; >> + } >> + } >> + >> + tzd->governor = new_gov; >> + tzd->governor_data = gov_data; >> + >> +exit: >> + mutex_unlock(&thermal_governor_lock); >> + return ret; >> +} >> + >> static int get_idr(struct idr *idr, struct mutex *lock, int *id) >> { >> int ret; >> @@ -734,22 +789,17 @@ policy_store(struct device *dev, struct >> device_attribute *attr, >> { >> int ret = -EINVAL; >> struct thermal_zone_device *tz = to_thermal_zone(dev); >> - struct thermal_governor *gov; >> char name[THERMAL_NAME_LENGTH]; >> >> snprintf(name, sizeof(name), "%s", buf); >> >> - mutex_lock(&thermal_governor_lock); >> - >> - gov = __find_governor(strim(name)); >> - if (!gov) >> + ret = thermal_update_governor(tz, strim(name), NULL); >> + if (ret < 0) >> goto exit; >> >> - tz->governor = gov; >> ret = count; >> >> exit: >> - mutex_unlock(&thermal_governor_lock); >> return ret; >> } >> >> @@ -1559,6 +1609,12 @@ struct thermal_zone_device >> *thermal_zone_device_register(const char *type, >> else >> tz->governor = __find_governor(DEFAULT_THERMAL_GOVERNOR); >> >> + if (tz->governor->start) { > > Note that tz->governor may be NULL at this time. > although this seems like a bug to me. > >> + result = tz->governor->start(tz); >> + if (result < 0) >> + tz->governor = NULL; >> + } >> + > why not invoke thermal_update_governor() directly here? > > thanks, > rui >> mutex_unlock(&thermal_governor_lock); >> >> if (!tz->tzp || !tz->tzp->no_hwmon) { >> @@ -1585,6 +1641,9 @@ struct thermal_zone_device >> *thermal_zone_device_register(const char *type, >> return tz; >> >> unregister: >> + if (tz->governor && tz->governor->stop) >> + tz->governor->stop(tz); >> + tz->governor = NULL; >> release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id); >> device_unregister(&tz->device); >> return ERR_PTR(result); >> @@ -1648,6 +1707,9 @@ void thermal_zone_device_unregister(struct >> thermal_zone_device *tz) >> device_remove_file(&tz->device, &dev_attr_policy); >> device_remove_file(&tz->device, &dev_attr_available_policies); >> remove_trip_attrs(tz); >> + >> + if (tz->governor && tz->governor->stop) >> + tz->governor->stop(tz); >> tz->governor = NULL; >> > >> thermal_remove_hwmon_sysfs(tz); >> diff --git a/include/linux/thermal.h b/include/linux/thermal.h >> index f7e11c7..a473736 100644 >> --- a/include/linux/thermal.h >> +++ b/include/linux/thermal.h >> @@ -177,6 +177,7 @@ struct thermal_zone_device { >> struct thermal_zone_device_ops *ops; >> const struct thermal_zone_params *tzp; >> struct thermal_governor *governor; >> + void *governor_data; >> struct list_head thermal_instances; >> struct idr idr; >> struct mutex lock; /* protect thermal_instances list */ >> @@ -187,6 +188,15 @@ struct thermal_zone_device { >> /* Structure that holds thermal governor information */ >> struct thermal_governor { >> char name[THERMAL_NAME_LENGTH]; >> + >> + /* >> + * The start and stop operations will be called when thermal zone is >> + * registered and when change governor via sysfs or driver in running >> + * time. >> + */ >> + int (*start)(struct thermal_zone_device *tz); >> + void (*stop)(struct thermal_zone_device *tz); >> + >> int (*throttle)(struct thermal_zone_device *tz, int trip); >> struct list_head governor_list; >> }; >> @@ -293,6 +303,8 @@ struct thermal_instance *get_thermal_instance(struct >> thermal_zone_device *, >> struct thermal_cooling_device *, int); >> void thermal_cdev_update(struct thermal_cooling_device *); >> void thermal_notify_framework(struct thermal_zone_device *, int); >> +int thermal_update_governor(struct thermal_zone_device *, const char *, >> + void *); >> >> #ifdef CONFIG_NET >> extern int thermal_generate_netlink_event(struct thermal_zone_device *tz, > > > > -- You have got to be excited about what you are doing. (L. Lamport) Eduardo Valentin
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