Lines Matching refs:changePowerStateTo
1356 /*! @function changePowerStateTo
1360 Calls to <code>changePowerStateTo</code>, <code>changePowerStateToPriv</code>, and a driver's power children all affect the power state of a driver. For legacy design reasons, they have overlapping functionality. Although you should call <code>changePowerStateToPriv</code> to change your device's power state, you might need to call <code>changePowerStateTo</code> in the following circumstances:
1362 <ul><li>If a driver will be using <code>changePowerStateToPriv</code> to change its power state, it should call <code>changePowerStateTo(0)</code> in its <code>start</code> routine to eliminate the influence <code>changePowerStateTo</code> has on power state calculations.
1364 <li>Call <code>changePowerStateTo</code> in conjunction with @link setIdleTimerPeriod setIdleTimerPeriod@/link and @link activityTickle activityTickle@/link to idle a driver into a low power state. For a driver with 3 power states, for example, <code>changePowerStateTo(1)</code> sets a minimum level of power state 1, such that the idle timer period may not set your device's power any lower than state 1.</ul>
1368 virtual IOReturn changePowerStateTo ( unsigned long ordinal );
1662 Three things affect driver power state: @link changePowerStateTo changePowerStateTo@/link, <code>changePowerStateToPriv</code>, and the desires of the driver's power plane children. Power management puts the device into the maximum state governed by those three entities.
1664 Drivers may eliminate the influence of the <code>changePowerStateTo</code> method on power state one of two ways. See @link powerOverrideOnPriv powerOverrideOnPriv@/link to ignore the method's influence, or call <code>changePowerStateTo(0)</code> in the driver's <code>start</code> routine to remove the <code>changePowerStateTo</code> method's power request.
1674 @discussion Power management normally keeps a device at the highest state required by its requests via @link changePowerStateTo changePowerStateTo@/link, @link changePowerStateToPriv changePowerStateToPriv@/link, and its children. However, a driver may ensure a lower power state than otherwise required by itself and its children using <code>powerOverrideOnPriv</code>.
1678 Turning on the override will initiate a power change if the driver's <code>changePowerStateToPriv</code> desired power state is different from the maximum of the <code>changePowerStateTo</code> desired power state and the children's desires.
1688 @discussion When a driver has enabled an override via @link powerOverrideOnPriv powerOverrideOnPriv@/link, it can disable it again by calling this method in its superclass. Disabling the override reverts to the default algorithm for determining a device's power state. The superclass will now keep the device at the highest state required by <code>changePowerStateTo</code>, <code>changePowerStateToPriv</code>, and its children.