Trouble Enabling HDMI on Custom Board with Jetpack 6

Hi all,

I want to enable HDMI on our custom board using JetPack 6. I’ve noticed that the Jetson_Orin_NX_and_Orin_Nano_series_Pinmux_Config_Template generated pinmux and Jetpack 6’s tegra234-mb1-bct-pinmux-p3767-hdmi-a03.dts have the same content and settings.

From previous experience, it should only be necessary to modify the L4T/jetson-orin-nano-devkit.conf by changing:

  • PINMUX_CONFIG to "tegra234-mb1-bct-pinmux-p3767-hdmi-a03.dtsi"
  • PMC_CONFIG to "tegra234-mb1-bct-padvoltage-p3767-hdmi-a03.dtsi"

Is that correct?

However, after flashing, xrandr still shows DP instead of HDMI. What else needs to be modified?

Thanks!

Most likely your device tree update didn’t happen.

Sorry, I just realized that you totally didn’t update the kerenl/uefi device tree. DCB image didn’t get changed, so it will of course be DP…

Hi Wayne,
Thank you for your reply, but I am currently a bit confused.

Are you referring to the modifications in the document Orin specific Display Configuration?

I have only made the following modifications in JP5:
Linux_for_Tegra/source/public/hardware/nvidia/platform/t23x/p3768/kernel-dts/tegra234-p3767-0000-p3768-0000-a0.dts

-#include "tegra234-dcb-p3767-0000-dp.dtsi"
+#include "tegra234-dcb-p3767-0000-hdmi.dtsi"

And in the file Linux_for_Tegra/p3768-0000+p3767-0000.conf:

-PINMUX_CONFIG="tegra234-mb1-bct-pinmux-p3767-dp-a03.dtsi";
-PMC_CONFIG="tegra234-mb1-bct-padvoltage-p3767-dp-a03.dtsi";
+PINMUX_CONFIG="tegra234-mb1-bct-pinmux-p3767-hdmi-a03.dtsi";
+PMC_CONFIG="tegra234-mb1-bct-padvoltage-p3767-hdmi-a03.dtsi";

After flashing and booting, xrandr will show HDMI."

However, in JP6, I cannot find the file tegra234-p3767-0000-p3768-0000-a0.dts.
Instead, there is a file named tegra234-p3768-0000-p3767-0000.dts?
But it does not include tegra234-dcb-p3767-0000-dp.dtsi.

Thanks

You could grep “dcb” in the source code files… there are not many files…

This is just how to trace code. Grep should be able find it.

Hi Wayne,
Thank you for your reply.
I know I can use grep to find files, but I’m not sure exactly which file I need to find and modify.
Is it this one: tegra234-dcb-p3767-0000-hdmi.dts?

Because in JP512, I just need to modify the two files mentioned above to switch from DP to HDMI

thanks

You could refer to p3509-a02-p3767-0000.conf and check the dtbo file of above file name and you will know what to do.

Hi Wayne,
Thank you for your reply.

Based on your response, the current configuration of p3509-a02-p3767-0000.conf is as follows:


source "${LDK_DIR}/p3768-0000-p3767-0000-a0.conf"

PINMUX_CONFIG="tegra234-mb1-bct-pinmux-p3767-hdmi-a03.dtsi";
PMC_CONFIG="tegra234-mb1-bct-padvoltage-p3767-hdmi-a03.dtsi";
OVERLAY_DTB_FILE+=",tegra234-dcb-p3767-0000-hdmi.dtbo";
DCE_OVERLAY_DTB_FILE="tegra234-dcb-p3767-0000-hdmi.dtbo";

It appears to already use tegra234-dcb-p3767-0000-hdmi.dts.

I checked this setting with the dcb_tool tool, as follows:

 ./dcb_tool -m tegra234-dcb-p3767-0000-hdmi.dts 
=== Modifying DCB blob ===

======================================================
|                DCB TOOL                            |
======================================================
|        Enter 0  => Show Input DCB                   |
|        Enter 1  => Modify DCB                       |
|        Enter 2  => Show modified DCB                |
|        Enter 3  => Show TMDS settings               |
|        Enter 4  => Show DP settings                 |
|        Enter 5  => Modify TMDS settings             |
|        Enter 6  => Show modified TMDS settings      |
|        Enter 7  => Modify DP settings               |
|        Enter 8  => Show modified DP settings        |
|        Enter 9.. => Exit                            |
======================================================
0

########## Tegra DCB BLOB ###############
########### Display Devices #############
Display Devices::
        Display Devices : [0]
                Type               : [TMDS]
                CCB                : [0]
                Heads              : 0:[Y] 1:[Y]
                Sor                : [0 ]
                HDMI capable       : [1]
                Connector          : [0]
                Bus                : [0]
############### CCB Entries ###############
CCB::
*CCB entries that have both I2C and AUX ports unused (value = 31) are not displayed
        CCB Index : 0
                I2C Port           : [6]
                AUX Port           : [0]
########### Connector entries #############
Connectors::
        Connector Index : 0x0
                Type               : [HDMI]
                Hotplug            : A:[Y]

======================================================
|                DCB TOOL                            |
======================================================
|        Enter 0  => Show Input DCB                   |
|        Enter 1  => Modify DCB                       |
|        Enter 2  => Show modified DCB                |
|        Enter 3  => Show TMDS settings               |
|        Enter 4  => Show DP settings                 |
|        Enter 5  => Modify TMDS settings             |
|        Enter 6  => Show modified TMDS settings      |
|        Enter 7  => Modify DP settings               |
|        Enter 8  => Show modified DP settings        |
|        Enter 9.. => Exit                            |
======================================================

It looks like it’s already HDMI, right? So I guess there’s no need for further modifications, or is there something else that needs to be modified?"

Thanks

No. I mean you could leverage this file.

1 Like

Hi Wayne,
Thank you for your help, it works now. It was my mistake.

Thanks again for your assistance.

Thank you.

Hi Wayne,
I have another issue to discuss.
From JP5 to the current JP6, many screens are unable to wake up from suspend mode under HDMI 4K resolution.
Is there a schedule for fixing this problem?

Thanks

Could you list the monitors that would hit this issue?