diff options
| author | Chanwoo Choi <cw00.choi@samsung.com> | 2016-03-22 07:44:03 +0300 |
|---|---|---|
| committer | MyungJoo Ham <myungjoo.ham@samsung.com> | 2016-05-03 05:20:07 +0300 |
| commit | 996133119f57334c38b020dbfaaac5b5eb127e29 (patch) | |
| tree | e197b5d3bc8b7816db57c3bff4b509c6eb111a1f /drivers/devfreq/Kconfig | |
| parent | 0fe3a66410a3ba96679be903f1e287d7a0a264a9 (diff) | |
| download | linux-996133119f57334c38b020dbfaaac5b5eb127e29.tar.xz | |
PM / devfreq: Add new passive governor
This patch adds the new passive governor for DEVFREQ framework. The following
governors are already present and used for DVFS (Dynamic Voltage and Frequency
Scaling) drivers. The following governors are independently used for one device
driver which don't give the influence to other device drviers and also don't
receive the effect from other device drivers.
- ondemand / performance / powersave / userspace
The passive governor depends on operation of parent driver with specific
governos extremely and is not able to decide the new frequency by oneself.
According to the decided new frequency of parent driver with governor,
the passive governor uses it to decide the appropriate frequency for own
device driver. The passive governor must need the following information
from device tree:
- the source clock and OPP tables
- the instance of parent device
For exameple,
there are one more devfreq device drivers which need to change their source
clock according to their utilization on runtime. But, they share the same
power line (e.g., regulator). So, specific device driver is operated as parent
with ondemand governor and then the rest device driver with passive governor
is influenced by parent device.
Suggested-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[tjakobi: Reported RCU locking issue and cw00.choi fix it]
Reported-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
[linux.amoon: Reported possible recursive locking and cw00.choi fix it]
Reported-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Diffstat (limited to 'drivers/devfreq/Kconfig')
| -rw-r--r-- | drivers/devfreq/Kconfig | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index cedda8f1e5eb..d260cd0219f6 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -64,6 +64,14 @@ config DEVFREQ_GOV_USERSPACE Otherwise, the governor does not change the frequency given at the initialization. +config DEVFREQ_GOV_PASSIVE + tristate "Passive" + help + Sets the frequency based on the frequency of its parent devfreq + device. This governor does not change the frequency by itself + through sysfs entries. The passive governor recommends that + devfreq device uses the OPP table to get the frequency/voltage. + comment "DEVFREQ Drivers" config ARM_EXYNOS_BUS_DEVFREQ |