We ordered an STM32MP257F-DK evaluation board - DigiKey part number "497-STM32MP257F-DK-ND" - on 25 September 2025 and had it delivered to Zürich.
On 15 October 2025 we ordered the same ST STM32MP257F-DK evaluation board with DigiKey part number "497-STM32MP257F-DK-ND" for delivery to one of our developers - Paul - working remotely.
Paul booted the ST STM32MP257F-DK board using the SD card that was supplied with it and was able to take it into and out of suspend-to-RAM with no problems however when we try to reproduce this with exactly the same steps with the ST STM32MP257F-DK here in Zürich it fails to waken from suspend-to-RAM.
We thought that it could be a difference in the images on the ST cards for the two boards so we copied the image for the SD card on the board delivered to Paul and tested it on the board here with exactly the same results.
We also checked that the WakeUp switch on the board is electrically functional - when I press it:
[ 290.372530] optee: no desc for optee IT:1
We also tested wakening from suspend-to-RAM using both the WakeUp switch on the board and the RTC (Real Time Clock) on the board here in Zürich without success.
Since there are several variants of this eval. board and several variants of this MPU it went through my mind that I could have made a mistake and accidentally had different boards delivered to Zürich and to Paul.
I checked the order for the ST MCU board that was delivered to here in Zürich which shows DigiKey part number "497-STM32MP257F-DK-ND" ordered on 25 September 2025 and delivered to Zürich - this seems to be exactly the same DigiKey part number as shown in the email from DigiKey to Paul on 15 October 2025:
DISCOVERY KIT STM32MP257F MPU
DigiKey part number
497-STM32MP257F-DK-ND
Manufacturer part number
STM32MP257F-DK
In both cases, we tested the STM32MP257F-DK board with a USB cable connected to provide power and serial debugging to a Linux machine.
The only difference we could find between the STM32MP257F-DK boards was several weeks difference the dates on which they were ordere.
I was wondering if you had any suggestions or if there were any known issues with suspend-to-RAM that could have caused this?
Thank you very much for your help,
Will
