Block Driver Power Cycle
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8/28/2008
The power management protocol supports power cycles that are transparent to applications.
Block Drivers that can be managed by Power Manager should advertise the PMCLASS_BLOCK_DEVICE interface. If a block driver does not advertise the PMCLASS_BLOCK_DEVICE interface, the device might hang during suspend. For more information, see Device Interfaces.
It is important that block device drivers handle the POWER_DOWN and POWER_UP system messages efficiently.
Like all device drivers, block device drivers must limit themselves to minimal, very fast processing of the POWER_DOWN message. To accomplish this, they should save any volatile state information in RAM, set a flag to indicate that power is about to turn off, and then exit.
POWER_ON processing is exactly like the processing for a regular card removal that follows an insertion.
Next, it checks the socket status and issues card-insertion notices for each socket with a card.
Then, the Device Manager launches its detection sequence and loads the appropriate driver for each card. For more information about the Device Manager, see Device Manager.
See Also
Concepts
Block Driver Architecture
Block Driver Samples
Block Driver Registry Settings
Block Driver Manager
Block Device File Systems
File System Loading and Unloading
Block Driver Interface
Block Driver Loading
Block Driver Installation
Block Driver Detection
Block Driver Access