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question on deep sleep

Li
Prodigy 90 points
Other Parts Discussed in Thread: OMAP-L138

Hi,

I am investigating on OMAP L138 deep sleep feature and encountered some problems that like to seek advice from TI.

 1. I am not able to use "rtcwake" command to put my device into deep sleep as it is not supported in my device. May i know can i use "echo mem > /sys/power/state" to put omap L138 to deep sleep? I tried out this command in my device and seem like it is not able to enter deep sleep.

2. i am trying to put my device into deep sleep by following the steps in section 10.10.1.1( Entering deep sleep using externally controlled wake up -- spruh77a). When i executing the steps for PLL bypass, my device seems to hang and not able to enter deep sleep. After i comment out the code for PLL bypass, i was  able to enter deep sleep but not able to wake up. Is there anything need to be done before entering deep sleep? (For eg: suspend process in linux kernel, clock gate peripherals, backup the required register context??)

3. There is a deep sleep suspend/resume timings provided by TI : http://processors.wiki.ti.com/index.php/DaVinci_PSP_03.22.00.02_Device_Driver_Features_and_Performance_Guide#Suspend.2FResume_timings. Does the measurement taken with omap-L138 EVM? The report show that it takes 242.665 msecs to suspend and 632.285 msecs to resume with default kernel. But when i tried to add up individual module resume timings, i am getting around 720ms instead of 632ms. Is 632ms is the total resume timings for all the module? May i know why there are some modules using extremely long time to resume (for eg: usb1 is using 99ms)?

Thanks a lot.

lipoh 

  • 0
    Prodigy 90 points

    Hi,

    I am investigating on OMAP L138 deep sleep feature and encountered some problems that like to seek advice from TI.

     1. I am not able to use "rtcwake" command to put my device into deep sleep as it is not supported in my device. May i know can i use "echo mem > /sys/power/state" to put omap L138 to deep sleep? I tried out this command in my device and seem like it is not able to enter deep sleep.

    2. i am trying to put my device into deep sleep by following the steps in section 10.10.1.1( Entering deep sleep using externally controlled wake up -- spruh77a). When i executing the steps for PLL bypass, my device seems to hang and not able to enter deep sleep. After i comment out the code for PLL bypass, i was  able to enter deep sleep but not able to wake up. Is there anything need to be done before entering deep sleep? (For eg: suspend process in linux kernel, clock gate peripherals, backup the required register context??)

    3. There is a deep sleep suspend/resume timings provided by TI : http://processors.wiki.ti.com/index.php/DaVinci_PSP_03.22.00.02_Device_Driver_Features_and_Performance_Guide#Suspend.2FResume_timings. Does the measurement taken with omap-L138 EVM? The report show that it takes 242.665 msecs to suspend and 632.285 msecs to resume with default kernel. But when i tried to add up individual module resume timings, i am getting around 720ms instead of 632ms. Is 632ms is the total resume timings for all the module? May i know why there are some modules using extremely long time to resume (for eg: usb1 is using 99ms)?

    4.After wake up from sleep, will the processor continue from the line where it entered deep sleep?

    Thanks a lot.

    lipoh