Supported on all platforms.
# echo +20 > /sys/class/rtc/rtc0/wakealarm
# echo mem > /sys/power/state
[ 83.628116] PM: suspend entry (deep)
[ 83.630834] Filesystems sync: 0.000 seconds
[ 83.635433] Freezing user space processes
[ 83.639941] Freezing user space processes completed (elapsed 0.001 seconds)
[ 83.645579] OOM killer disabled.
[ 83.648848] Freezing remaining freezable tasks
[ 83.654341] Freezing remaining freezable tasks completed (elapsed 0.000 seconds)
[ 83.660730] printk: Suspending console(s) (use no_console_suspend to debug)
With theses commands the system is suspended and resumes 20 second later.
You can also push the WAKE UP button to wake up the board.
NOTICE: CPU: STM32MP157FAC Rev.Z
NOTICE: Model: STMicroelectronics STM32MP157F-DK2 Discovery Board
NOTICE: Board: MB1272 Var4.0 Rev.C-02
NOTICE: BL2: v2.10-stm32mp1-r1.0(release):custom()
NOTICE: BL2: Built : 10:18:08, Jan 6 2025
NOTICE: BL2: Booting BL32
[ 83.852705] Disabling non-boot CPUs ...
[ 83.854164] CPU1 killed.
[ 83.855013] Enabling non-boot CPUs ...
[ 83.857006] CPU1 is up
[ 83.910619] usb usb2: root hub lost power or was reset
[ 84.259445] onboard-usb-hub 2-1: reset high-speed USB device number 2 using ehci-platform
[ 84.606387] OOM killer enabled.
[ 84.609521] Restarting tasks ... done.
[ 84.613633] random: crng reseeded on system resumption
[ 84.618856] PM: suspend exit
Here is the wake up logs.
Notes:
The Bluetooth driver does not support suspend-to-RAM. To use Bluetooth
after a suspend-to-RAM operation, you must reload the hci_uart module
using the following commands:
# modprobe -r hci_uart
# modprobe hci_uart
On the STM32MP135F-DK, suspend-to-RAM does not work correctly. To address this, you must disable console suspend and activate the Ethernet interface. This keeps a few clocks active, enabling OP-TEE OS to resume correctly from suspend.
# echo N > /sys/module/printk/parameters/console_suspend
# ip link set eth0 up
# echo mem > /sys/power/state