[NCS1.9.1]System off mode abnormal problem

[zero]

Dear Support Team,
I test system off mode under the following conditions:
NCS1.9.1; nRF52840-DK and nRF52-DK; added dk_button_init initialization code in the system off example.
After nRF52840-DK and or nRF52-DK burn compiled firmware, you can see the following log output:

*** Booting Zephyr OS build v2.7.99-ncs1-1  ***

nrf52840dk_nrf52840 system off demo
Retained data not supported
Sleep 2 s
Entering system off; press BUTTON1 to restart

Test method: Press button1 on the DK continuously and quickly within 2 seconds.
Result: the device gets bricked and the program freezes.
The following is my program, please help analyze the reason and give a solution, thank you for your support!

system_off.7z
Remarks: Only need to compile and burn to nRF52840-DK or nRF52-DK, press button1 continuously and quickly to reproduce.

[Priyanka]

Hi,

So we finally got to the culprit. 

The problem is that  dk_buttons_and_leds.c does this little thing that when a button is pressed, it disables the interrupts, and manually scans the GPIOs to see when they are released. So if you are continuously pressing it, or even holding it down, there does not seem to be a release and interrupt is disabled.

So you can have a small workaround by introducing a check to prevent the system from going into sleep. I will attach the modified code here. THe check is named keep_alive.

6165.system_off.zip

Hope this helps. 

[zero]

Hi

Thank you for your support, there are no problems under simple testing.