i.MX7D and Colibri Evaluation board power off

I’m using ubuntu 14.04 installed in VM, Toradex version 2.6, Colibri evaluation board and i.MX7D.

Until now I used i.MX7S. From today I had to switch module and use i.MX7D.

I read again the documentation for linux image, kenel, device tree and uboot customization and compilation and i noticed that the unique part to rebuild is the device tree. It’s correct?

I inserted i.MX7D module into Colibri evaluation board and loaded all of the software component on the i.MX7D.

The boot is ok and also my application start correctly but the image on the screen is slightly flickering.
Also if i try to power off the module (with linux command “poweroff”) the module seems to power off (the screen become black) but after a seconds the “RESET_OUT” signal led become red and the screen is powered on again with various colour on it.

if i move the i.MX7D module to an Iris carrier board, this problem disappear.
If i use the i.MX7S module on the Colibri evaluation board, this problem disappear.

It seems a problem related to i.MX7D and Colibri evaluation board working together.

Thanks for any help you can give.

Today I tried another i.MX7 module, without modification directly from the factory.

Using the “poweroff” command always happens the same problem.

What am I missing? Jumper configuration on Colibri evaluation board? Or?

Thanks for any help you can give.

What screen are you using and how is it connected to the module?

Also what module version are you using?

The problem is likely that the iMX7D is able to power off completely. Earlier version of the iMX7S (V1.1A and older) are not able to power off the module due to a SoC bug (the SNVS subsystem is not accessible).

Now powering off the module does not power off the Carrier Board, hence the state of all the peripherals on the Carrier Board at that time is not defined. The Colibri standard does not define a “power off” pin or similar… (note that our Apalis standard has such a pin). If you need to have a defined state on the carrier board after power off, you should define a GPIO as power off pin and include such circuitry in your Carrier board. The GPIO article on our developer website has an example how to specify/use a power off GPIO.