Goal: Drive two extended displays from the single DisplayPort output.
What we have verified
Orin → DP-to-HDMI adapter → single HDMI monitor: Works (DFP-1: Internal TMDS).
Orin → SUNIX DPH2001-D5 (DP→2×HDMI MST hub): Fails completely.
No displays are detected.
card1-DP-1: disconnected
No HPD, AUX, or EDID activity appears in dmesg.
Repeated cmd:0x731341 result 0xffff.
Xorg reports the output mode as "NULL".
The system remains stable (no reset or crash).
The same MST hub, monitors, and cables work correctly on a Windows PC (two displays), so the hub, cables, and monitors appear to be functioning properly.
We are aware of WayneWWW’s statement:
“Only MST on pure DP is supported. DP to 2x HDMI is not guaranteed.” (Thread 261811, comment #4)
Q1
Can NVIDIA officially confirm that off-the-shelf DP→2×HDMI MST hubs are not supported on AGX Orin (R36.4.4)?
Based on thread 304863, it appears that DP→2×HDMI can be achieved only with a custom design using a VMM5320-class MST bridge, rather than with a commercially available DP→2×HDMI MST hub. Is this understanding correct?
Q2
Since pure DisplayPort MST is supported, could you recommend a specific commercial, off-the-shelf DP→2×DP MST hub that has been validated on AGX Orin running R36.4.4?
We are looking for a purchasable product (manufacturer and part number), not just a bridge IC.
If no commercial product has been validated, could you please recommend:
The key distinction is between DP MST capability and validation of a specific external MST hub.
DP MST support
Jetson AGX Orin supports DisplayPort MST. The Jetson Linux R36.4.4 Developer Guide lists DP MST support for two different streams on different monitors. The Orin Series SoC TRM also lists DisplayPort Multistream and Dual-MST as hardware capabilities in the Display Controller chapter.
However, these documents do not validate a particular external MST hub. DP-to-2×HDMI through an MST hub is not an NVIDIA-validated configuration, so compatibility is not guaranteed. This does not mean that every DP-to-2×HDMI hub is technically incapable of working.
VMM5320 and commercial MST hubs
The VMM5320 result in the referenced thread is a user-reported implementation, not an NVIDIA-validated reference design. It does not establish that a custom VMM5320 design is the only possible solution.
We do not have a commercially available DP-to-2×DP or DP-to-2×HDMI MST hub validated for Jetson AGX Orin on R36.4.4, nor a preferred MST bridge chipset to recommend. NVIDIA’s MST validation used DP monitors connected by MST daisy-chaining, as clarified in this related discussion.
Xorg, DCB, and device tree
There is no NVIDIA-documented MST-hub-specific xorg.conf, DCB, or device-tree configuration. DCB, pinmux, and device tree describe the base DP/HDMI output of the custom carrier board; they do not qualify a downstream MST hub.
In the reported failure, the DP connector remains disconnected and there is no HPD, AUX, or EDID activity. Based on those symptoms, the failure appears to occur at the display-link detection stage, before X11 output layout is applied. An xorg.conf change is therefore not expected to address this detection failure.
Recommendation: For an NVIDIA-tested topology, use native DisplayPort monitors with MST daisy-chaining. If HDMI outputs or a standalone commercial hub are required, the selected hub and complete display configuration would need to be qualified as part of the product design; NVIDIA cannot guarantee compatibility or recommend a validated part number for this configuration.
“Thank you for your response. I’ve decided not to use the MST feature and am planning to connect to a USB-C monitor using a DP-to-C cable instead. Is this also not supported? Does the official documentation provide any support for this? For your reference, I am using a Jetson 6.2.1 AGX Orin devkit.”
Our support scope covers the DisplayPort output. Signal conversion through a third-party DP-to-USB-C adapter or cable is outside NVIDIA’s validation scope, so we cannot guarantee compatibility or operation with a specific adapter/cable and USB-C monitor combination.