The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Possible dependencies:
5fdded844892 ("PM/devfreq: governor: Add a private governor_data for governor") 54cb5740526a ("PM / devfreq: Fix multiple kernel-doc warnings") 27dbc542f651 ("PM / devfreq: Use PM QoS for sysfs min/max_freq") 05d7ae15cfb1 ("PM / devfreq: Add PM QoS support") 46cecc0bf095 ("PM / devfreq: Introduce get_freq_range helper") cf451adfa392 ("PM / devfreq: add tracing for scheduling work") 2f061fd0c2d8 ("PM / devfreq: stopping the governor before device_unregister()") df5cf4a36178 ("PM / devfreq: Fix handling of min/max_freq == 0") d0e464205b8a ("PM / devfreq: Drop custom MIN/MAX macros") 2c2cb1e6b05b ("PM / devfreq: Init user limits from OPP limits, not viceversa") 2d803dc8f7a5 ("PM / devfreq: use put_device() instead of kfree()") f1d981eaecf8 ("PM / devfreq: Use the available min/max frequency") 1051e2c304b5 ("Revert "PM / devfreq: Add show_one macro to delete the duplicate code"") ab8f58ad72c4 ("PM / devfreq: Set min/max_freq when adding the devfreq device") 9e14de1077e9 ("PM / devfreq: Fix memory leak when fail to register device") 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs") 29b6968b05b6 ("PM / devfreq: Remove unnecessary separate _remove_devfreq()") 924b9111a14f ("PM / devfreq: Don't delete sysfs group twice")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5fdded8448924e3631d466eea499b11606c43640 Mon Sep 17 00:00:00 2001 From: Kant Fan kant@allwinnertech.com Date: Tue, 25 Oct 2022 15:21:09 +0800 Subject: [PATCH] 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
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, diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 34aab4dd336c..4dc7cda4fd46 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -152,8 +152,8 @@ struct devfreq_stats { * @max_state: count of entry present in the frequency table. * @previous_freq: previously configured frequency value. * @last_status: devfreq user device info, performance statistics - * @data: Private data of the governor. The devfreq framework does not - * touch this. + * @data: devfreq driver pass to governors, governor should not change it. + * @governor_data: private data for governors, devfreq core doesn't touch it. * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) * @scaling_min_freq: Limit minimum frequency requested by OPP interface @@ -193,7 +193,8 @@ struct devfreq { unsigned long previous_freq; struct devfreq_dev_status last_status;
- void *data; /* private data for governors */ + void *data; + void *governor_data;
struct dev_pm_qos_request user_min_freq_req; struct dev_pm_qos_request user_max_freq_req;