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J784S4XEVM: How to resume the EVM from Sleep Mode

Part Number: J784S4XEVM

Tool/software:

Hi

I am trying to validate the sleep mode in the EVM using the command echo mem > /sys/power/state. It seems the EVM is going into sleep mode as per below logs and also on power supply I could see the drop of current consumption by approx 6mA as soon the command is given. Can you let me know how to resume the EVM back from the sleep state?

Also on pressing the WARM switch at SW9 the current consumption further reduces to approx 20mA. Can you please let me know the functionality of this switch?

The SDK version for J784S4 is 10_00_00_08 & boot mode is eMMC.

Thanks,

Arjav Parikh

  • Hi,

    I am trying to validate the sleep mode in the EVM using the command echo mem > /sys/power/state. It seems the EVM is going into sleep mode as per below logs and also on power supply I could see the drop of current consumption by approx 6mA as soon the command is given. Can you let me know how to resume the EVM back from the sleep state?

    There is no support for suspend to RAM in software for J784s4 & hence you are observing the behavior.

    Also on pressing the WARM switch at SW9 the current consumption further reduces to approx 20mA. Can you please let me know the functionality of this switch?


    Best Regards,
    Keerthy

  • Hi Keerthy,

    There is no support for suspend to RAM in software for J784s4 & hence you are observing the behavior.

    But as per current situation the EVM is going into Suspend to Idle [s2idle] which actually means to system sleep state i.e one of the low power states. So, in this situation I expect that the EVM should resume again. I also tried using command  "rtcwake -s 10 -m mem -d rtc0" to wake up system back after 10 secs; but no effect.

    Thanks,

    Arjav Parikh

  • Hi Arjav,

    That's the default Linux behavior. A lot many other softwares will need to add support to S2R. We do not have software support for the suspend to RAM.

    Best regards,

    Keerthy 

  • Hi Keerthy,

    So this default behaviour of S2Idle will be supported?

    I am aware that currently S2R is not supported in the current SDK but as per my understanding S2R and S2idle are different power modes and working is also different.

    Thanks,

    Arjav Parikh

  • Hi Arjav,

    So this default behaviour of S2Idle will be supported

    Both S2Idle & S2RAM have similar flow. S2Idle is a shallow state and S2RAM is a deeper sleep state. Current SDK does not support either of them.
    Hence you are observing the hang.

    - Keerthy

  • Hi Keerthy,

    Thanks for the update.

    Is there any plan to include support for S2RAM in SDK?

    As this is a business requirement is it possible to add or port the support for S2Idle & S2RAM in latest SDK version available by referring other TI based SOC SDK's where S2RAM support is available. Maybe with TI guidance can try for it.

    Thanks,

    Arjav Parikh

  • Hello, 

    10.0 is the latest SDK and since it's a complex multi core feature. This is not targetted for the next SDK which is 10.1. I do not have a confirmed target version of SDK.

    Best regards,

    Keerthy