7e6fdd4bad
Prepare devfreq core framework to support devices which can idle. When device idleness is detected perhaps through runtime-pm, need some mechanism to suspend devfreq load monitoring and resume back when device is online. Present code continues monitoring unless device is removed from devfreq core. This patch introduces following design changes, - use per device work instead of global work to monitor device load. This enables suspend/resume of device devfreq and reduces monitoring code complexity. - decouple delayed work based load monitoring logic from core by introducing helpers functions to be used by governors. This provides flexibility for governors either to use delayed work based monitoring functions or to implement their own mechanism. - devfreq core interacts with governors via events to perform specific actions. These events include start/stop devfreq. This sets ground for adding suspend/resume events. The devfreq apis are not modified and are kept intact. Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
45 lines
1.6 KiB
Plaintext
45 lines
1.6 KiB
Plaintext
What: /sys/class/devfreq/.../
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Date: September 2011
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Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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Description:
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Provide a place in sysfs for the devfreq objects.
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This allows accessing various devfreq specific variables.
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The name of devfreq object denoted as ... is same as the
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name of device using devfreq.
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What: /sys/class/devfreq/.../governor
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Date: September 2011
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Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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Description:
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The /sys/class/devfreq/.../governor shows the name of the
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governor used by the corresponding devfreq object.
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What: /sys/class/devfreq/.../cur_freq
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Date: September 2011
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Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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Description:
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The /sys/class/devfreq/.../cur_freq shows the current
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frequency of the corresponding devfreq object.
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What: /sys/class/devfreq/.../polling_interval
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Date: September 2011
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Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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Description:
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The /sys/class/devfreq/.../polling_interval shows and sets
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the requested polling interval of the corresponding devfreq
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object. The values are represented in ms. If the value is
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less than 1 jiffy, it is considered to be 0, which means
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no polling. This value is meaningless if the governor is
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not polling; thus. If the governor is not using
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devfreq-provided central polling
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(/sys/class/devfreq/.../central_polling is 0), this value
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may be useless.
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What: /sys/class/devfreq/.../userspace/set_freq
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Date: September 2011
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Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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Description:
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The /sys/class/devfreq/.../userspace/set_freq shows and
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sets the requested frequency for the devfreq object if
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userspace governor is in effect.
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