Is it possible to upgrade a basic USB-C to have USB-C Alternate Mode

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In relation to my previous post (How to get an HP Elitebook 840 G4 on a Universal USB-C dock to be Thunderbolt compatible?), I have a ThinkPad USB-C Dock Gen 2 (Type 40AS) and would like to use this dock on my HP EliteBook when I'm not using my Lenovo since based on the Product Page of the Dock, it's generic and should work with other non-Lenovo PCs.

However, based on the PC Manual, I found out that my HP Elitebook only has a basic USB-C port and doesn't support video modes (alternate modes).

Is it possible to install a software or a driver to enable Alternate Mode or perhaps purchase a hardware dongle/adapter? I wouldn't want to buy a new laptop just to support video over USB-C.

I also found out from HP Forums that HP is somehow limiting their USB Type-C ports not to support Alternate Mode.

Thank you.

Best Answer

No, Alt Mode essentially repurposes the USB C Superspeed signalling lanes to transmit video signals instead of the USB Superspeed data.

From How DisplayPort Alt Mode is Enabled over a USB Type-C Cable

With USB 3.2, two or four of the differential high speed lanes can be used for Alt Mode. If USB data transmission is required, it will use two lanes, leaving the remaining two for Alt Mode, otherwise, all four lanes are available for Alt Mode.

Essentially it requires the use of a USB Type-C™ DisplayPort™ ALT Mode Crosspoint Switch such as the TUSB1046-DCI from Texas Instruments. This device essentially switches over the high speed data lanes and the DisplayPort output from the GPU.

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If that switch isn't there then no software can do anything to emulate it.

As an alternative you can use different "DisplayLink" adaptors such as the DL-1x5 adaptors which are essentially low speed USB based graphics adaptors. I wouldn't use them for gaming, but they should manage to display an image on a monitor.

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