Howto wakeup after suspend to ram

Showing results for 
Search instead for 
Did you mean: 

Howto wakeup after suspend to ram

Contributor IV


after setting the i.MX board to suspend to ram a can't wake it up.

echo mem > /sys/power/state

How can I configure the board to wakeup on USB event, Magic Packet or GPIO?
Do I have to recompile the kernel?

Labels (2)
2 Replies

NXP Employee
NXP Employee

Hi, Holger

     You can wake up system from suspend via debug UART, RTC or keypad. I do NOT know what board and what kernel you are using, below are some example based on i.MX6Q SabreSD board with v3.0.35 kernel, for different board, the UART and RTC alarm still can work as wakeup source, but the sys interface path may be different. If you have other question, please tell me the board and the software version, I will give you a guide.

1. Wake up by debug UART:

echo enabled > /sys/devices/platform/imx-uart.0/tty/ttymxc0/power/wakeup;

Then click any key in debug console, system will wake up.

2. Wake up by RTC alarm:

echo +5 > /sys/class/rtc/rtc0/wakealarm;

system will wake up 5 second after suspend.

3. Just press power key(SW3) when system suspend to wake up it.

Contributor III

Hi Yongcai,

We are using imx53 based design and trying to wake up the system using UART.

We too followed the same command for setting UART as wake source.But not able to wake the system.

echo enabled > /sys/devices/platform/imx-uart.0/tty/ttymxc0/power/wakeup;

We are using Kernel version 2.6.35.

0 Kudos