We have an issue with iMX6DL and power-saving. On our custom-board we have implemented an LPDDR2 RAM (Micron EDB8164B4 ) to achieve better low-power. When we bring Linux in Suspend-to-RAM it goes to sleep but pushing an wake-up button results in an reboot instead of wake-up and back to normal operation. On sabresd-board (iMX6DL) the same Linux kernel works as expected.
I have found following thread with similar issue:
but unfortunately this patch applies to an older kernel version, we use Linux 4.1.15 from NXP git repository. For u-boot we use version 2016.11-rc3, however we have done all configuration and calibration for LPDDR2 in u-boot, RAM stress test has been also passed successfully.
Here is the output of “uname –a”
Linux imx6dlsabresd 4.1.15-1.2.0+g77f6154 #1 SMP PREEMPT Mon Nov 28 11:05:20 CET 2016 armv7l GNU/Linux
Console snapshot when system is going to sleep and push button for wake-up.
root@imx6dlsabresd:~# echo mem > /sys/power/state
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.005 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
Suspending console(s) (use no_console_suspend to debug)
>>>>>> BUTTON FOR WAKE-UP HAS BEEN PUSCHED <<<<<<
U-Boot 2016.11-rc3-svn209 (Dec 14 2016 - 10:47:19 +0100)
Many thanks in advanced for your support.