Other Parts Discussed in Thread: TEST2
Hi,
I have a custom board using TPS65988 and TUSB1046 that converts a DP connection from the source PC to a USB-C output DP-ALT compatible sink. From my PC as the source, I have the board hooked up to a DP sink analyzer and I can successfully stream to it, but run into issues when porting the same setup to drive a different external display sink.
I am using the EZ-PD protocol analyzer (logs attached below) and see that the DP-ALT link is being successfully negotiated (AUX channels are hooked correctly and mux control for 4L DP is set correctly). However, upon successful negotiation, I do not see the display connection under Settings->System->Display. If I open up NVIDIA's test utility, it does see the external display, but unable to retrieve information about it (BPC, etc).
Please see my TPS65988 configurations attached. Port1 is the dedicated DP-ALT output port. Under "Display Port Capabilities", if I change the "DP Receptacle Indication" and "Supports USB Gen 2 signaling" to plug and unchecked (as in the test3 file), respectively, I see my host monitor actually begins to flicker and establishes connection for a split second (I see my external display in settings pop up). But, something in the chain is forcing a hard reset without giving a clear message why. I have attached the PD analyzer log for it as well below.
Is there something obvious I'm missing here? I didn't think the issue is related to the TPS65988 configuration given the ALT mode is successfully negotiating, but the changes in test3 that show the external display for a split second is making me question it (both show a successful negotiation). Thanks and appreciate any insights!
