[Jetson nano] HDMI is always connected even cable is not plug in and resolution error

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

We have issue with HDMI as below description:

  1. HDMI is always on connected status although cable don’t plug in
    Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
    HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 890mm x 500mm
    1280x720 60.00*+ 59.94 50.00
    720x576 50.00
    720x480 59.94
    640x480 59.94
    DP-0 connected primary 600x1024+0+0 right (normal left inverted right x axis y axis) 150mm x 100mm
    1024x600 60.04*+
  2. Screen resolution is not correct.
    when i plug in hdmi to device, log show as below:
    ac@vsm:~$ xrandr
    Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384
    HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 890mm x 500mm
    1280x720 60.00*+ 59.94 50.00
    720x576 50.00
    720x480 59.94
    640x480 59.94
    DP-0 connected primary 600x1024+0+0 right (normal left inverted right x axis y axis) 150mm x 100mm
    1024x600 60.04*+

Screen resolution correct is 600x1024
This issue lead to touch issue
So, please help me for resolve this issue
Thank you

3

  1. For your HDMI issue, can you share me the dmesg? I guess the EDID is not read from your board at all.

  2. As for the DP case, can you share the edid of your DP monitor?

4
  1. I would like share to you dmesg log. Please check attachment file.
  2. Could you guide me for get edid?
    Thank you!
    hdmi_issue_log.txt (64.3 KB)
5
  1. From the dmesg, below log shows tegra side is not able to read the edid from your monitor at all. Fallback edid is a hardcoded one we wrote in driver.
    This means the display driver is not in expected behavior. What is the environment? Is this a custom carrier board or just NV nano developer kit?
[    1.255381] tegradc tegradc.0: hdmi: edid read failed
[    1.260494] tegradc tegradc.0: hdmi: using fallback edid
[    1.260577] tegradc tegradc.0: blank - powerdown
  1. The method to dump edid is as below. 0,1 indicate the DP and HDMI here. Thus, we shall have 2 edid.

sudo cat /sys/kernel/debug/tegradc.X/edid #X=0,1,2.

6
  1. What is the environment? Is this a custom carrier board of just NV nano developer kit?

there is not special environment, hdmi is not plug in. This is custom carrier board of just NV nano developer kit

  1. The method to dump edid is as below. 0,1 indicate the DP and HDMI here. Thus, we shall have 2 edid.

ac@vsm:~$ sudo cat /sys/kernel/debug/tegradc.0/edid
00 ff ff ff ff ff ff 00 3a c4 01 00 00 00 00 00
05 1b 01 03 80 59 32 8c 0a e2 bd a1 5b 4a 98 24
15 47 4a 20 00 00 01 01 01 01 01 01 01 01 01 01
01 01 01 01 01 01 01 1d 00 72 51 d0 1e 20 6e 28
55 00 75 f2 31 00 00 1e 01 1d 00 bc 52 d0 1e 20
b8 28 55 40 75 f2 31 00 00 1e 00 00 00 fd 00 32
3d 0f 2e 08 00 0a 20 20 20 20 20 20 00 00 00 fc
00 4e 56 49 44 49 41 00 0a 20 20 20 20 20 01 f9
02 03 19 71 46 84 13 05 14 03 12 23 09 07 07 83
01 00 00 65 03 0c 00 10 00 01 1d 80 18 71 1c 16
20 58 2c 25 00 75 f2 31 00 00 9e 01 1d 80 d0 72
1c 16 20 10 2c 25 80 75 f2 31 00 00 9e 8c 0a d0
8a 20 e0 2d 10 10 3e 96 00 75 f2 31 00 00 18 8c
0a d0 90 20 40 31 20 0c 40 55 00 75 f2 31 00 00
18 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ca

ac@vsm:~$ sudo cat /sys/kernel/debug/tegradc.1/edid
00 ff ff ff ff ff ff 00 04 81 04 00 01 00 00 00
01 11 01 03 80 0f 0a 00 0a 00 00 00 00 00 00 00
00 00 00 00 00 00 01 01 01 01 01 01 01 01 01 01
01 01 01 01 01 01 24 13 00 20 41 58 16 20 05 0d
23 00 ff ff 00 00 00 18 00 00 00 10 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 10 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 10
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12

Thank you!

7

What kind of HDMI monitor is that? Do you use any kind of adapter on it?

As for your DP, the edid says the resolution is 1024x600… thus, the display driver has nothing wrong…

image

8

Sorry that my previous comment has typo.

My question was: is this a custom board or just a NV devkit?

9

This is a custom board

10

What kind of HDMI monitor is that? Do you use any kind of adapter on it?

Sorry, i don’t understand “kind of HDMI monitor”, hdmi is same with devkit. Device is not connect to external monitor. We also don’t use any kind of adapter on it
Thank you

11

Then please check your hardware design and check why i2c is not able to read the edid first…

Do you understand that we are talking about different issue here?

12

Then please check your hardware design and check why i2c is not able to read the edid first…

yes, i will check again.
Do you understand that we are talking about different issue here?
sorry about my understand ^^. I think that we should focus on hdmi always connected issue firstly.
Thank you!

13

The HDMI connected problem should not happen at all.

I just tried on my devkit and when hdmi cable is disconnected, xrandr will remove other modes.

Thus, you should check your hardware design regarding the hotplug detection first. And that may affect your edid read as well.

Plug out

$ xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
HDMI-0 disconnected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
  1920x1080 (0x144) 148.500MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz

Plug in
$ xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
HDMI-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 290mm
   1920x1080     60.00*+  59.95    50.00  
   1680x1050     59.96  
   1600x1200     60.01  
   1600x900      60.00  
   1440x900      59.89  
   1280x1024     60.00  
   1280x800      59.81  
   1280x720      60.00    59.94    50.00  
   1024x768      60.01  
   800x600       60.32  
   720x576       50.00  
   720x480       59.94  
   720x400       70.04  
   640x480       59.94
1 Like
15

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.