Windows embedded compact 7 is not going to suspend mode RRS feed

  • Question

  • Hi All,

    We are having a OMAP4470 board running on Windows embedded compact 7 on it. 

    The WEC7 device implements the default power manager model.
    The SystemActivity timer and UserActivity timers are configured as suggested in MSDN -

    All the three state transistion timeouts registries- AcUserIdle, AcSystemIdle, AcSuspend are configured to timeouts in seconds.
    When the device is left idle with no tasks running on the device, it is expected to transistion from 
    On State -> UserIdle State -> SystemIdle State-> Suspend state,  when the corresponding timers expire.
    The device transistions from On State -> UserIdle State -> SystemIdle State but it does not enter suspend.

    As we debugged we found that that SystemActivity timer is reset very frequently and this causes the SystemIdle timeout to reload again.Hence the device does not enter Suspend state.

    We are unable to trace which process is causing the SystemActivity timer reset.
    Please suggest how we can check which process/activity is not allowing the system to go to suspend state?


    Friday, September 20, 2013 7:01 AM

All replies

  • Probable cause of this behavior is due to the reg setting related to suspend state.

    Try forcing device to go to suspend state by this transition On State -> UserIdle State -> Suspend or programmatic force it to go to suspend state using Set SystemPowerState() API. If the system shows the same behavior. I suppose there is a reg setting overriding suspend to system idle.

    If the reg setting is ok then check the OAL function and debug it.

    --- Misbah

    Senior Design Engineer T.E.S Electroni Solutions (Bangalore-India)

    Monday, September 23, 2013 5:26 AM
  • Hi usbpro,

    I am working with the same configuration like you and facing the exact same issue. Are you able to find out what is causing the SystemActivity timer to reset? Thank you. 

    Friday, June 20, 2014 8:22 AM
  • It is found that by removing the highlighted entry below from common.reg, the device will be able to suspend after system idle timeout. Anyone knows which of the storage devices is triggering this event? Thanks

    "Folder"="Mounted Volume"

    • Edited by tiger3687 Tuesday, July 1, 2014 4:05 AM
    Tuesday, July 1, 2014 4:05 AM