DART-MX8M suspend: Difference between revisions
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= Measuring SOM current consumption in suspend = | = Measuring SOM current consumption in suspend = | ||
To measure SOM current consumption remove resistor R15 on DT8MCustomBoard or R58 On Symphony | To measure the SOM current consumption remove resistor R15 on DT8MCustomBoard or R58 On Symphony-Board and connect an ammeter in its place.<br> | ||
It is recommended to boot from eMMC to get accurate measurement. | It is recommended to boot from eMMC to get an accurate measurement. | ||
Revision as of 10:38, 16 November 2020
Suspend to RAM
This state offers significant power savings as everything in the system is put into a low-power state, except for memory, which is placed into the self-refresh mode to retain its contents.
To suspend to RAM execute the following command:
# pm-suspend
Wake up
There are many possible ways to wake up from suspend.
A few examples:
- Pushing the ON/OFF button (when present on the board)
- Pushing a button on the board which has the boolean property "wakeup-source" set in its device tree node (under gpio_keys), e.g.:
gpio-keys { compatible = "gpio-keys"; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_gpio_keys>; ... back { label = "Back"; gpios = <&gpio4 6 GPIO_ACTIVE_LOW>; linux,code = <KEY_BACK>; wakeup-source; }; };
- Pressing the capacitive touch which has the "wakeup-source" property set in its device tree node, e.g.:
ft5x06_ts: ft5x06_ts@38 { status = "disabled"; compatible = "edt,edt-ft5x06"; reg = <0x38>; reset-gpios = <&gpio4 5 GPIO_ACTIVE_LOW>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_touch>; interrupt-parent = <&gpio1>; interrupts = <14 0>; touchscreen-size-x = <800>; touchscreen-size-y = <480>; touchscreen-inverted-x; touchscreen-inverted-y; wakeup-source; };
Measuring SOM current consumption in suspend
To measure the SOM current consumption remove resistor R15 on DT8MCustomBoard or R58 On Symphony-Board and connect an ammeter in its place.
It is recommended to boot from eMMC to get an accurate measurement.