Hello,

> According to MPC7455 User's Manual, the bit defined as HID_DOZE  in
> arch/powerpc/include/oea/hid.h is not DOZE mode for this family. It is
> HIGH_BAT_ENABLE, for additional address space mapping. 
Ah, this explains it.

> This gets turned off
> on cpu_subr.c
> 
> /* Select NAP mode. */
> hid0 &= ~(HID0_DOZE | HID0_NAP | HID0_SLEEP);
> hid0 |= HID0_NAP | HID0_DPM;
and then 		
powersave = 0;		/* but don't use it */

I think powersave should be set to 1 for 7455 v2.1 and newer and 7457, at least that's what the Darwin source suggests.

have fun
Michael