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authorKant Fan <kant@allwinnertech.com>2022-10-25 10:21:09 +0300
committerChanwoo Choi <cw00.choi@samsung.com>2022-11-20 14:49:51 +0300
commit5fdded8448924e3631d466eea499b11606c43640 (patch)
tree192e2197a073d7216d661bb27ef432f45715876d /drivers/devfreq
parent094226ad94f471a9f19e8f8e7140a09c2625abaa (diff)
downloadlinux-5fdded8448924e3631d466eea499b11606c43640.tar.xz
PM/devfreq: governor: Add a private governor_data for governor
The member void *data in the structure devfreq can be overwrite by governor_userspace. For example: 1. The device driver assigned the devfreq governor to simple_ondemand by the function devfreq_add_device() and init the devfreq member void *data to a pointer of a static structure devfreq_simple_ondemand_data by the function devfreq_add_device(). 2. The user changed the devfreq governor to userspace by the command "echo userspace > /sys/class/devfreq/.../governor". 3. The governor userspace alloced a dynamic memory for the struct userspace_data and assigend the member void *data of devfreq to this memory by the function userspace_init(). 4. The user changed the devfreq governor back to simple_ondemand by the command "echo simple_ondemand > /sys/class/devfreq/.../governor". 5. The governor userspace exited and assigned the member void *data in the structure devfreq to NULL by the function userspace_exit(). 6. The governor simple_ondemand fetched the static information of devfreq_simple_ondemand_data in the function devfreq_simple_ondemand_func() but the member void *data of devfreq was assigned to NULL by the function userspace_exit(). 7. The information of upthreshold and downdifferential is lost and the governor simple_ondemand can't work correctly. The member void *data in the structure devfreq is designed for a static pointer used in a governor and inited by the function devfreq_add_device(). This patch add an element named governor_data in the devfreq structure which can be used by a governor(E.g userspace) who want to assign a private data to do some private things. Fixes: ce26c5bb9569 ("PM / devfreq: Add basic governors") Cc: stable@vger.kernel.org # 5.10+ Reviewed-by: Chanwoo Choi <cwchoi00@gmail.com> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kant Fan <kant@allwinnertech.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Diffstat (limited to 'drivers/devfreq')
-rw-r--r--drivers/devfreq/devfreq.c6
-rw-r--r--drivers/devfreq/governor_userspace.c12
2 files changed, 8 insertions, 10 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 63347a5ae599..8c5f6f7fca11 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -776,8 +776,7 @@ static void remove_sysfs_files(struct devfreq *devfreq,
* @dev: the device to add devfreq feature.
* @profile: device-specific profile to run devfreq.
* @governor_name: name of the policy to choose frequency.
- * @data: private data for the governor. The devfreq framework does not
- * touch this value.
+ * @data: devfreq driver pass to governors, governor should not change it.
*/
struct devfreq *devfreq_add_device(struct device *dev,
struct devfreq_dev_profile *profile,
@@ -1011,8 +1010,7 @@ static void devm_devfreq_dev_release(struct device *dev, void *res)
* @dev: the device to add devfreq feature.
* @profile: device-specific profile to run devfreq.
* @governor_name: name of the policy to choose frequency.
- * @data: private data for the governor. The devfreq framework does not
- * touch this value.
+ * @data: devfreq driver pass to governors, governor should not change it.
*
* This function manages automatically the memory of devfreq device using device
* resource management and simplify the free operation for memory of devfreq
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
index ab9db7adb3ad..d69672ccacc4 100644
--- a/drivers/devfreq/governor_userspace.c
+++ b/drivers/devfreq/governor_userspace.c
@@ -21,7 +21,7 @@ struct userspace_data {
static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)
{
- struct userspace_data *data = df->data;
+ struct userspace_data *data = df->governor_data;
if (data->valid)
*freq = data->user_frequency;
@@ -40,7 +40,7 @@ static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr,
int err = 0;
mutex_lock(&devfreq->lock);
- data = devfreq->data;
+ data = devfreq->governor_data;
sscanf(buf, "%lu", &wanted);
data->user_frequency = wanted;
@@ -60,7 +60,7 @@ static ssize_t set_freq_show(struct device *dev,
int err = 0;
mutex_lock(&devfreq->lock);
- data = devfreq->data;
+ data = devfreq->governor_data;
if (data->valid)
err = sprintf(buf, "%lu\n", data->user_frequency);
@@ -91,7 +91,7 @@ static int userspace_init(struct devfreq *devfreq)
goto out;
}
data->valid = false;
- devfreq->data = data;
+ devfreq->governor_data = data;
err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group);
out:
@@ -107,8 +107,8 @@ static void userspace_exit(struct devfreq *devfreq)
if (devfreq->dev.kobj.sd)
sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
- kfree(devfreq->data);
- devfreq->data = NULL;
+ kfree(devfreq->governor_data);
+ devfreq->governor_data = NULL;
}
static int devfreq_userspace_handler(struct devfreq *devfreq,