Error --"-sh: echo: write error: Device or resource busy" while running app 'OpenAMP_TTY_echo_wakeup' on board STM32MP157C-DK2

[SElle]

I'd like to test the standby mode on the board ​STM32MP157C-DK2,so I run the application 'OpenAMP_TTY_echo_wakeup' by following the doc -- readme.txt  in STM32Cube MP1 package. However ,once I run the command 

$ echo mem > /sys/power/state

  to move CA7 in CStop mode , it will report such error:

[ 281.518965] PM: Syncing filesystems ... done.
 
[ 281.546418] Freezing user space processes ... (elapsed 0.001 seconds) done.
 
[ 281.553742] OOM killer disabled.
 
[ 281.557176] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
 
[ 281.564607] Suspending console(s) (use no_console_suspend to debug)
 
[ 281.629016] dwc2 49000000.usb-otg: suspending usb gadget configfs-gadget
 
[ 281.629035] dwc2 49000000.usb-otg: dwc2_hsotg_ep_disable: called for ep0
 
[ 281.629045] dwc2 49000000.usb-otg: dwc2_hsotg_ep_disable: called for ep0
 
[ 281.694403] stm32-dma 48001000.dma: Suspend is prevented by Chan 1
 
[ 281.694436] dpm_run_callback(): platform_pm_suspend+0x0/0x48 returns -16
 
[ 281.694447] PM: Device 48001000.dma failed to suspend: error -16
 
[ 281.694458] PM: Some devices failed to suspend, or early wake event detected
 
[ 281.705449] dwmac4: Master AXI performs any burst length
 
[ 281.705484] stm32-dwmac 5800a000.ethernet eth0: No Safety Features support found
 
[ 281.747812] dwc2 49000000.usb-otg: resuming usb gadget configfs-gadget
 
[ 282.290600] OOM killer enabled.
 
[ 282.293712] Restarting tasks ... done.
 
[ 282.344351] PM: suspend exit
 
-sh: echo: write error: Device or resource busy
 

Do you know the reason for this problem?

[IYetk]

I got the same error like you but I couldn't solve the problem so far. How did you switch between engineering boot mode and production boot mode ? Do you mean the eclipse debug configuration tab in the attachment ?

other question : Our scenario is the second scenario in the readme file. There it says "Set Exti line 61 (IPCC interrupt CPU1) as source of wakeup". So I modified the code and changed 62 to 61 and some other lines related. Did you modify your code as well ? If yes, could you please send me modified codes if possible.

I will appricate a possible answer very muc, thanks a lot !

[PatrickF]

Engineering mode set in SW4STM32 should be also set on the board using BOOT[2:0] = 0b100