Disable HDMI interface Linux, Colibri iMX6

Technical Support
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1

We have a problem where our custom circuit board using Colibri iMX6DL crashes when using external small PSU, but not if powered from Ethernet (PoE). Our HW developer says it might be because Linux (the Toradex “stable” from EasyInstaller) might be enabling the built-in HDMI on the Colibri iMX6 !

How do I configure Linux, so it doesn’t enable the HDMI ?

Best regards
J

2

Here is a dmesg log

link text

3

What exactly do you mean by “using external small PSU”?

As for HDMI, this should really use the hot-plug detect GPIO.

4

We have had a HW guy create a custom board. We will not be using HDMI.
His design cannot handle the power draw when HDMI is active.
We are thus looking to make sure HDMS on the iMX6 is not enabled, as specs say:
Colibri iMX6 490 mA / 615 mA with HDMI active - and the extra 125 mA seems to be too much .

So can you see in the dmesg log if HMDI IS enabled ? And if if is, how can I disable it ?

Thank you for your help.
J.

5

So can you see in the dmesg log if HMDI IS enabled ? And if if is, how can I disable it ?

It does not look like it. What does xrandr say?

You may also go ahead and actually answer some of my questions…

6

Thanks Marcel,
The only question I see from you is “What exactly do you mean by “using external small PSU”?”
and I thought I had answered that.
We have had a custom carrier board designed for the iMX6, and this board has two options for power:
A regular mini-USB PSU delivering 5v & 1,5A , or using PoE (which seems to support higher load).
Our supplier of this board has tested it successfully under Win CE, but not under Linux (where it crashes), and he suspects that Linux has a higher power-draw.
Everything works in the Iris Carrier board (which has a 12v 1,5 A PSU)…
Anyway, we will order some iMX7 CoM’s which have lower power draw (and no HDMI, which we don’t use anyway).
Thanks.
J

7

Sure, you may also answer my question concerning xrandr output.

8

Sorry:

root@colibri-imx6:~# xrandr
Screen 0: minimum 240 x 240, current 800 x 480, maximum 8192 x 8192
DISP3 BG connected 800x480+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   U:800x480p-59  59.48*+
9

Hi, Thanks for your answer. That does not look like that HDMI is enabled. Could you state which other peripheral did you connect to the board?