|POWER(9E)||Driver Entry Points||POWER(9E)|
#include <sys/ddi.h> #include <sys/sunddi.h> int prefixpower(dev_info_t *dip, int component, int level);
The level argument is the driver-defined power level to which the component needs to be set. Except for power level 0, which is interpreted by the framework to mean "powered off," the interpretation of level is entirely up to the driver.
The component argument is the component of the device to be power-managed. The interpretation of component is entirely up to the driver.
When a requested power transition would cause the device to lose state, the driver must save the state of the device in memory. When a requested power transition requires state to be restored, the driver must restore that state.
If a requested power transition for one component requires another component to change power state before it can be completed, the driver must call pm_raise_power(9F) to get the other component changed, and the power(9E) entry point must support being re-entered.
If the system requests an inappropriate power transition for the device (for example, a request to power down a device which has just become busy), then the power level should not be changed and power should return DDI_FAILURE.
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
Writing Device Drivers
Using Power Management
|September 16, 2016||OmniOS|