STM32U5 consumes more current using power management

[vibhor-meshram]

Describe the bug
I am using nucleo_u575zi_q board. I want to implement shutdown mode using power management scheme and wake up the MCU using an external interrupt. For starters I am testing zephyr\samples\boards\stm32\power_mgmt\blinky example to test the basic power management. I am using zephyr 3.10 version.

I created power states nodes in nucleo_u575zi_q.dts file (since nodes were not present there).
power-states {
stop0: state0 {
compatible = "zephyr,power-state";
power-state-name = "suspend-to-idle";
substate-id = <1>;
min-residency-us = <100>;
};
stop1: state1 {
compatible = "zephyr,power-state";
power-state-name = "suspend-to-idle";
substate-id = <2>;
min-residency-us = <500>;
};
stop2: state2 {
compatible = "zephyr,power-state";
power-state-name = "suspend-to-idle";
substate-id = <3>;
min-residency-us = <900>;
};

&cpu0 {
cpu-power-states = <&stop0 &stop1 &stop2>;
};

In the blinky proj.conf file following is the configuration I have:

CONFIG_PM=y
CONFIG_PM_DEVICE=y
CONFIG_PM_DEVICE_RUNTIME=y
CONFIG_CONSOLE=n
CONFIG_SERIAL=n

Expected behavior
When CONFIG_PM is set to y, the MCU should consume low power than what it would consume in active state (CONFIG_PM=n).

Observation
If
CONFIG_PM=y
CONFIG_PM_DEVICE=y
CONFIG_PM_DEVICE_RUNTIME=y
CONFIG_CONSOLE=n
CONFIG_SERIAL=n

Current Consumption = 12.8 mA
LED stops blinking

If
CONFIG_PM=n
CONFIG_PM_DEVICE=n
CONFIG_PM_DEVICE_RUNTIME=n
CONFIG_CONSOLE=n
CONFIG_SERIAL=n

Current Consumption = 7.3 mA
LED is blinking after every 2 seconds
**

Impact
High

Environment (please complete the following information):

• OS: Windows
• Toolchain Zephyr SDK V 3.10

[erwango]

@vibhor-meshram Did you enable lptim node in order to use it as a LP ticker ?

&clk_lse {
	status = "okay";
}

&lptim1 {
	clocks = <&rcc STM32_CLOCK_BUS_APB3 0x00000800>,
		 <&rcc STM32_SRC_LSE LPTIM1_SEL(3)>;
	status = "okay";
};

[vibhor-meshram]

Hi @erwango I added the above nodes. No change in in output. Adding my dts file for your reference.
nucleo_u575zi_q-common.txt

[erwango]

Here is my test with the provided configuration.
Measurements were done using stm32l562e_dk & STM32 CubeMonitor-Power.
There's a bit of noise (which may be due to ST-Link, I haven't checked deeper on the board doc), but consumption level is around 100uA, which I think is acceptable to demonstrate stop modes.

This was achieved using samples/boards/stm32/power_mgmt/blinky and the configuration provided above on zephyr-v3.1.0-4437-g162d435908
Please note that I had to reset the board to override default debug setting.

[erwango]

@vibhor-meshram I'm closing the point as can't be reproduced. Please re-open if you have more inputs.