AnsweredAssumed Answered

i.MX6 HDMI detection problem

Question asked by Pavel Krejsa on Sep 30, 2014
Latest reply on Nov 26, 2014 by Sainath Naidu

Dear all,

 

I am facing problem with HDMI output from i.MX6.

First of all some introduction of my HW and SW:

1) It is on our own custom design based on Sabre lite and wandboard. Difference is applied MCU - MCIMX6D4AVT10AC

2) Kernel 3.10.17 1.0.0. GA with custom DT file to customize peripherials.

3) Filesystem is ubuntu provided by Robert Nelson from this wiki http://eewiki.net/

 

Problem:

For some reason, HDMI output is not shown on the monitor, even though on both reference boards it works.

 

When i focus on dmesg, i see for reference board

 

ubuntu@arm:~$ dmesg | grep hdmi

Kernel command line: console=ttymxc0,115200 root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait video== mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24,bpp=16 dmfc=3

mxc_sdc_fb fb.26: register mxc display driver hdmi

mxc_hdmi 20e0000.hdmi_video: Detected HDMI controller 0x13:0x1a:0xa0:0xc1

imx-audio-hdmi sound-hdmi.24:  hdmi-hifi <-> hdmi_audio.16 mapping ok

  #2: imx-hdmi-soc

 

and for custom board:

 

ubuntu@arm:~$ dmesg | grep hdmi

Kernel command line: console=ttymxc1,115200 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait video== mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24,bpp=16 dmfc=3

mxc_sdc_fb fb.22: register mxc display driver hdmi

mxc_hdmi 20e0000.hdmi_video: Detected HDMI controller 0x0:0x0:0x0:0x0

imx-audio-hdmi sound-hdmi.23:  hdmi-hifi <-> hdmi_audio.16 mapping ok

  #0: imx-hdmi-soc

 

 

Now I focus on detected HDMI controler - it has 0x0 in all fields. I tried direct access to the

HDMI_DESIGN_ID and HDMI_REVISION_ID

using devregs:

reference board:

HDMI_REVISION_ID:0x00120001     =0x1a

HDMI_PRODUCT_ID0:0x00120002     =0xa0

custom board

HDMI_REVISION_ID:0x00120001 =  0x00

HDMI_PRODUCT_ID0:0x00120002 = 0x00

 

 

This version of the MCU hsould not have VPU support, but still should have HDMI output according to the datasheet.

May be anyone so kind and focus me on the issue, what I am doing wrong? Should HDMI be switched on somewhere?

 

Thank all for the ideas and help.

 

Best Regards

Pavel Krejsa

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