diff options
| author | Kant Fan <kant@allwinnertech.com> | 2022-10-25 15:21:09 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-14 10:16:31 +0100 |
| commit | cea018aaf7218a50bdbf17540b311e6b2982d883 (patch) | |
| tree | 286f75222b2d78eb9022818bbbead641b97a18d2 /include | |
| parent | d1d73c303458a148f8b77fca99aa71074c69eb49 (diff) | |
PM/devfreq: governor: Add a private governor_data for governor
commit 5fdded8448924e3631d466eea499b11606c43640 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/devfreq.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 121a2430d7f7..fc4c7ad49cee 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -146,8 +146,8 @@ struct devfreq_stats { * @work: delayed work for load monitoring. * @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 @@ -183,7 +183,8 @@ 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; |