OSPM / power managent of devices/drivers

NTDEV
1

hi

(1) I’ve been reading the ACPI Spec, and I’m wondering what OSPM is? Is this the Operating System Power Manager that sends the IRP_MJ_POWER irps down to drivers?

Also, what role does OSPM play in powering up and down devices (for power management)?
Is there something more than sending and management the IRP_MJ_POWER, etc?

I’m also trying to determine how to lower the power state of devices when the PC is in the S0 (normal running) power state. I do not have the source code to the function driver (power power owner).

Some methods to do this are:

  1. Use WMI to enable/disable the device
  2. Use the SetupDi* apis to disable and enable the device

(2) Is there other methods?
For example, an you use power policy settings to change a device power state? (SetActivePwrScheme api, etc)?
Can you use the global and machine power policy to do this? I haven’t seen anything in the DDK, but perhaps there are some subtle implications I’m missing.

By the way, the OS in question is Windows XP.

thanks
Sharon

2

hi

(1) I’ve been reading the ACPI Spec, and I’m wondering what OSPM is? Is this the Operating System Power Manager that sends the IRP_MJ_POWER irps down to drivers?

Also, what role does OSPM play in powering up and down devices (for power management)?
Is there something more than sending and management the IRP_MJ_POWER, etc?

I’m also trying to determine how to lower the power state of devices when the PC is in the S0 (normal running) power state. I do not have the source code to the function driver (power power owner).

Some methods to do this are:

  1. Use WMI to enable/disable the device
  2. Use the SetupDi* apis to disable and enable the device

(2) Is there other methods?
For example, an you use power policy settings to change a device power state? (SetActivePwrScheme api, etc)?
Can you use the global and machine power policy to do this? I haven’t seen anything in the DDK, but perhaps there are some subtle implications I’m missing.

By the way, the OS in question is Windows XP.

thanks
Sharon