43f93b8ead
BugLink: https://bugs.launchpad.net/bugs/2003914
[ Upstream commit 5fdded8448924e3631d466eea499b11606c43640 ]
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:
|
||
|---|---|---|
| .. | ||
| event | ||
| Kconfig | ||
| Makefile | ||
| devfreq-event.c | ||
| devfreq.c | ||
| exynos-bus.c | ||
| governor.h | ||
| governor_passive.c | ||
| governor_performance.c | ||
| governor_powersave.c | ||
| governor_simpleondemand.c | ||
| governor_userspace.c | ||
| rk3399_dmc.c | ||
| tegra20-devfreq.c | ||
| tegra30-devfreq.c | ||