Board support request: public DTS/DTB support for ASUS Vivobook 14 X1407QA

[pir0c0pter0]

Hi,

I would like to request public board support / DTS availability for the ASUS Vivobook 14 X1407QA (Snapdragon X X1-26-100, X1E80100 family).

Current Linux status on this machine:

• Linux can be booted only via workarounds using the ASUS Zenbook A14 DTB path
• I could not find a public DTS/DTB for the X1407QA itself
• As a result, several model-specific fixes are still being carried locally at runtime
• USB-C DisplayPort alt-mode is already working, but USB4/TB3 enablement still needs both upstream kernel work and board-specific topology
• The Insyde UEFI on this laptop does not seem to allow the usual DTB override paths, so public board support is especially important

What has already been validated locally:

• Fedora 44 boots and is usable on the machine
• multiple model-specific runtime fixes are already working locally (keyboard, battery, brightness, camera RGB, audio, etc.)
• both USB-C ports work for plain USB and DisplayPort alt-mode
• the dock/device side can be detected far enough to confirm this is not a basic cable or port failure

Where progress currently stops without upstream/vendor help:

• there is still no public DTS/DTB for the X1407QA itself
• USB4/TB3 tunneling is blocked by the missing Qualcomm X1E80100 host/router support in public kernels
• board-specific USB4 topology still needs the proper DTS/DT wiring for this laptop
• the platform firmware/UCSI path also appears to need platform-specific support/quirks

In other words: this is no longer at the stage of "we have not tried enough locally". There has already been significant progress on real hardware, but continued work now depends on public board support and/or guidance from Qualcomm on the correct DTS/DTB path for this retail laptop.

What would help:

• A public DTS/DTSI/DTB path for the X1407QA, or confirmation that support is planned
• Guidance on whether this request belongs in kernel-topics, qcom-dtb-metadata, kernel, or another Qualcomm Linux repository
• If there is already internal DTB metadata for this retail laptop, whether it can be published and/or upstreamed
• Any recommended branch, patch series, or board-support work-in-progress that is appropriate for external testing

Useful identifiers:

• Model: ASUS Vivobook 14 X1407QA
• SoC: Snapdragon X X1-26-100 (X1E80100 family)
• Ports of interest: 2x USB-C with USB4/TB3-capable hardware

I documented the current Linux findings here:

• Repository: https://github.com/pir0c0pter0/fedora-vivobook-x1407q
• USB4/TB3 investigation: https://github.com/pir0c0pter0/fedora-vivobook-x1407q/blob/main/USB4-TB3-investigation.md
• Upstream patch checklist: https://github.com/pir0c0pter0/fedora-vivobook-x1407q/blob/main/docs/research/2026-03-24-usb4-upstream-patch-checklist.md

I can test DTS branches, kernel patches, or any board-support series on the real hardware and report results.

If this request should live in qcom-dtb-metadata or another repo instead, please let me know and I can re-file it there.

Thanks.

[pir0c0pter0]

Additional technical summary from testing on the real X1407QA:

• Current Fedora/kernel builds do not create /sys/bus/usb4/ on this machine
• Plain USB-C DisplayPort alt-mode is already working on both ports
• data_role may initialize incorrectly, but forcing host mode is enough to make a TB3 dock appear as a USB Billboard fallback device
• UCSI on this platform reports alt-mode details, but the normal firmware path still does not allow us to complete TB3/USB4 tunneling
• The remaining blocker no longer looks like a simple local configuration issue; it appears to require the missing Qualcomm X1E80100 USB4 host/router support plus the correct board-specific DTS topology for this laptop

So the system is already far enough along to show that the hardware path is there, but it currently stops at the point where public board support / upstream platform support is needed.

If Qualcomm has an internal or work-in-progress DTS / DT metadata path for this exact retail laptop, I am available to test and report results.