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Resume the Linux System using Keypad

Question asked by Anjalik Krishna on Nov 30, 2017
Latest reply on Jan 12, 2018 by Anjalik Krishna


 I am doing power management in Linux 3.14.38 . I need to configure the touch and keypad as wakesource.


After suspending the system using echo mem > /sys/power state command  the keypad suspend routine is getting called from imx-keypad.c file and for resume I am pressing a key and the resume function is called and gets hang. System does not look like resumed and the LCD backlight also in off state


Prints are :


echo mem > /sys/power/state
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.001 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.

 imx_kbd_suspend ------>
PM: suspend of devices complete after 70.704 msecs
PM: suspend devices took 0.080 seconds
PM: late suspend of devices complete after 0.535 msecs
PM: noirq suspend of devices complete after 0.634 msecs
Disabling non-boot CPUs ...
PM: noirq resume of devices complete after 0.290 msecs
PM: early resume of devices complete after 0.413 msecs


 imx_kbd_resume ----->
 114 irq kpp
 imx_kbd_resume end ----->


In dtsi file I tried adding wakeup-source property but it didnt work.

  kpp: kpp@020b8000 {
                          compatible = "fsl,imx6sl-kpp", "fsl,imx21-kpp";
                          reg = <0x020b8000 0x4000>;
                          interrupts = <0 82 0x04>;
                          clocks = <&clks 0>;



Any help would be appreciated