On 21. 3. 7. 오후 6:45, Daniel Lezcano wrote:
Currently the default behavior is to manually having the devfreq
backend to register themselves as a devfreq cooling device.
Instead of adding the code in the drivers for the thermal cooling
device registering, let's provide a flag in the devfreq's profile to
tell the common devfreq code to register the newly created devfreq as
a cooling device.
Suggested-by: Chanwoo Choi <cwcho...@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezc...@linaro.org>
---
V3:
- Rebased on linux-pm branch without units.h
- Set the cdev to NULL in case of error
- Added description for the cdev field in the devfreq structure
V2:
- Added is_cooling_device boolean in profile structure
- Register cooling device when the is_cooling_device boolean is set
- Remove devfreq cooling device registration in the backend drivers
V1:
- Register devfreq as a cooling device unconditionnally
---
drivers/devfreq/devfreq.c | 13 +++++++++++++
include/linux/devfreq.h | 8 ++++++++
2 files changed, 21 insertions(+)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index bf3047896e41..cf64aeec468f 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -11,6 +11,7 @@
#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/debugfs.h>
+#include <linux/devfreq_cooling.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -26,6 +27,7 @@
#include <linux/hrtimer.h>
#include <linux/of.h>
#include <linux/pm_qos.h>
+#include <linux/thermal.h>
#include "governor.h"
#define CREATE_TRACE_POINTS
@@ -935,6 +937,15 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_unlock(&devfreq_list_lock);
+ if (devfreq->profile->is_cooling_device) {
+ devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
+ if (IS_ERR(devfreq->cdev)) {
+ dev_info(dev, "Failed to register devfreq "
+ "cooling device\n");
+ devfreq->cdev = NULL;
+ }
+ }
+
return devfreq;
err_init:
@@ -960,6 +971,8 @@ int devfreq_remove_device(struct devfreq *devfreq)
if (!devfreq)
return -EINVAL;
+ thermal_cooling_device_unregister(devfreq->cdev);
I have a question. Why don't you use devfreq_cooling_unregister()?
When thermal_cooling_device_unregister(), how can we remove
the pm_qos_request of devfreq device?
+
if (devfreq->governor) {
devfreq->governor->event_handler(devfreq,
DEVFREQ_GOV_STOP, NULL);
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 26ea0850be9b..aba7ace11b72 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -98,11 +98,15 @@ struct devfreq_dev_status {
* @freq_table: Optional list of frequencies to support
statistics
* and freq_table must be generated in ascending order.
* @max_state: The size of freq_table.
+ *
+ * @is_cooling_device: A self-explanatory boolean giving the device a
+ * cooling effect property.
*/
struct devfreq_dev_profile {
unsigned long initial_freq;
unsigned int polling_ms;
enum devfreq_timer timer;
+ bool is_cooling_device;
int (*target)(struct device *dev, unsigned long *freq, u32 flags);
int (*get_dev_status)(struct device *dev,
@@ -156,6 +160,7 @@ struct devfreq_stats {
* @suspend_count: suspend requests counter for a device.
* @stats: Statistics of devfreq device behavior
* @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER
notifier
+ * @cdev: Cooling device pointer if the devfreq has cooling property
* @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY
* @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY
*
@@ -198,6 +203,9 @@ struct devfreq {
struct srcu_notifier_head transition_notifier_list;
+ /* Pointer to the cooling device if used for thermal mitigation */
+ struct thermal_cooling_device *cdev;
+
struct notifier_block nb_min;
struct notifier_block nb_max;
};
--
Best Regards,
Samsung Electronics
Chanwoo Choi
