You can find the registry settings for the suspend mode in:
It is not required to restart the system after changes made in these registry keys. You can use IOCTL_HAL_RELOADPMPARAMS to reload the settings.
If no setting is present, the default value is taken. Just add the values to the registry to change them.
[HKLM\System\PM] "NoSleepOnPowerFail"=dword:1 ;Added option to disable the Automatic entry in DeepSleep ;on Voltage Fault detection. (This was causing troubles in ;some cases where current consumption was high). Defualt = 0; "SDRAMAPD"=dword:1 ;SDRAM Autopower down ;1(default) Enabled in CPU idle ;2 always enabled ;3 always off "Idle"=dword:1 ;CPU Idle mode ;0 CPU will never enter Idle mode ;1 (default) CPU will enter Idle mode "IdlePatch"=dword:0 ;CPU Idle patch selection ;0 CPU enters Idlemode immediately (default for PXA270 and PXA3xx when not running @ 806MHz or 403MHz) ;1 Method one (default for PXA3xx @ 806MHz or 403MHz) ; Change freq. to 104, idle, then back to 806 (requires full freq change) ;2 Method two Change freq. to 403, idle, then back to 806 (faster as it can be done with turbo freq change but not confirmed by Marvell)