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Linux/AM5728: Future AM57xx suspend support ?

Part Number: AM5728


Tool/software: Linux

Hi,

It is thought that linux kernel of present ti-processor-sdk-linux am57xx 03.00.03.04 does not support the following suspend.
Is there the plan to support in the future?
1.standby mode
2.standby+DDR selfrefresh mode

It is thought that linux kernel of present ti-processor-sdk-linux am57xx 03.00.03.04 does not support the following suspend.
Is there the plan to support in the future?
1.standby mode
2.standby+DDR selfrefresh mode

I executed the following commands for trial.
According to the log, it seems to work to modulle off+WFI

echo mem > /sys/power/state

root@am57xx-evm:~# echo mem > /sys/power/state
[ 60.418632] PM: Syncing filesystems ... done.
[ 60.962884] Freezing user space processes ... (elapsed 0.001 seconds) done.
[ 60.971261] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[ 61.162151] PM: suspend of devices complete after 180.551 msecs
[ 61.171542] PM: late suspend of devices complete after 3.436 msecs
[ 61.181116] PM: noirq suspend of devices complete after 3.359 msecs
[ 61.187412] Disabling non-boot CPUs ...
[ 61.238917] CPU1: shutdown
[ 61.269234] Powerdomain (ipu_pwrdm) didn't enter target state 0
[ 61.269234] Could not enter target state in pm_suspend
[ 61.269234] A possible cause could be an old bootloader - try u-boot >= v2012.07
[ 61.269318] Enabling non-boot CPUs ...
[ 61.319263] CPU1: smp_ops.cpu_die() returned, trying to resuscitate
[ 61.325799] CPU1 is up
[ 61.330892] PM: noirq resume of devices complete after 2.717 msecs

[ 61.339637] PM: early resume of devices complete after 2.084 msecs
[ 61.348561] net eth0: initializing cpsw version 1.15 (0)
[ 61.353902] net eth0: initialized cpsw ale version 1.4
[ 61.359120] net eth0: ALE Table size 1024
[ 61.450852] net eth0: phy found : id is : 0x221622
[ 61.698382] ata1: SATA link down (SStatus 0 SControl 300)
[ 61.979924] usb 1-1: reset high-speed USB device number 2 using xhci-hcd
[ 62.278658] PM: resume of devices complete after 932.807 msecs
[ 62.287507] Restarting tasks ... done.

Best Regards,
Shigehiro Tsuda

  • Hi Shigehiro,

    Latest AM57x PSDK 3.03.00.04 (based on kernel 4.4.41) support suspend/resume. Refer to the below wik page for details:

    processors.wiki.ti.com/.../Linux_Core_Power_Management_User's_Guide_(v4.4)

    Regards,
    Pavel
  • Hi Pavel,

    Thank you for quick reply.
    I confirmed wiki page of your answer.
    AM57xx seems to surely support it.

    Will the source of suspend/resume be as follows?
    ti-processor-sdk-linux-am57xx-evm-03.03.00.04\board-support\linux-4.4.41+gitAUTOINC+f9f6f0db2d-gf9f6f0db2d\arch\arm\mach-omap2\pm44xx.c
    ti-processor-sdk-linux-am57xx-evm-03.03.00.04\board-support\linux-4.4.41+gitAUTOINC+f9f6f0db2d-gf9f6f0db2d\arch\arm\mach-omap2\sleep44xx.s

    Because the source which built became OMAP44xx device, I thought that AM57xx did not support it.

    Best Regards,
    Shigehiro Tsuda
  • shigehiro tsuda said:
    Will the source of suspend/resume be as follows?
    ti-processor-sdk-linux-am57xx-evm-03.03.00.04\board-support\linux-4.4.41+gitAUTOINC+f9f6f0db2d-gf9f6f0db2d\arch\arm\mach-omap2\pm44xx.c
    ti-processor-sdk-linux-am57xx-evm-03.03.00.04\board-support\linux-4.4.41+gitAUTOINC+f9f6f0db2d-gf9f6f0db2d\arch\arm\mach-omap2\sleep44xx.s

    Yes

    shigehiro tsuda said:
    Because the source which built became OMAP44xx device, I thought that AM57xx did not support it.

    This is also for OMAP54xx and DRA7x device. DRA7x and AM57x share the same code, see below file:

    ti-processor-sdk-linux-am57xx-evm-03.03.00.04\board-support\linux-4.4.41+gitAUTOINC+f9f6f0db2d-gf9f6f0db2d\arch\arm\mach-omap2\board-generic.c

    Regards,
    Pavel

  • Hi Pavel,

    Thank you for your kind and quick response.
    I understood according to your answer.

    Best Regards,
    Shigehiro Tsuda