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acrn-kernel/drivers/devfreq
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Kant Fan 5052a96b21 PM/devfreq: governor: Add a private governor_data for governor 
commit 5fdded8448 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: ce26c5bb95 ("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>
 		2023-01-07 11:11:40 +01:00
..
event PM / devfreq: rockchip-dfi: Fix an error message 2022-09-26 03:59:43 +09:00
Kconfig PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver 2022-07-15 11:40:08 +09:00
Makefile PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver 2022-07-15 11:40:08 +09:00
devfreq-event.c
…
devfreq.c PM/devfreq: governor: Add a private governor_data for governor 2023-01-07 11:11:40 +01:00
exynos-bus.c OPP updates for 5.20-rc1 2022-08-03 17:49:38 +02:00
governor.h
…
governor_passive.c PM / devfreq: passive: revert an editing accident in SPDX-License line 2022-06-30 05:11:17 +09:00
governor_performance.c
…
governor_powersave.c
…
governor_simpleondemand.c
…
governor_userspace.c PM/devfreq: governor: Add a private governor_data for governor 2023-01-07 11:11:40 +01:00
imx-bus.c Char / Misc driver changes for 6.0-rc1 2022-08-04 11:05:48 -07:00
imx8m-ddrc.c
…
mtk-cci-devfreq.c PM / devfreq: mtk-cci: Handle sram regulator probe deferral 2022-09-26 03:59:12 +09:00
rk3399_dmc.c
…
sun8i-a33-mbus.c
…
tegra30-devfreq.c OPP updates for 5.20-rc1 2022-08-03 17:49:38 +02:00