TPS65982: Display Port Video bypass from TPS65982+HD3SS460 at USB-C port 1 to USB-C Port 2 TPS65982+HD3SS460

Hi Jeffrey,
thanks for the quick answer! Yes, lets make this feature works :)
I have correct configuration, same as you proposed. Also when i solder wires to Display port connector (istead of USB-C port 2) - i can get video out of MacBook, up to 5K.
So, looks like MUX is controlled correctly and HDP (TX/RX) set to GPIO 4.
MacBook is detecting the monitor (it detect that LG UltraFine is connected, but video is absent), and saying that monitor is attached, but MacBook became to be very slow.... I can observe at oscilloscoupe that HPD signal has frequency 3 Hz - I assume that due to that 3Hz MacBook has some issue with perforance.

When i am connecting external monitor via Display port wires (Samsung 4K) - everything works perfect.
Any ideas?..
Best regards,
Sergii

Hi Sergii,

To confirm and further claify, the connections you are making are the same as the screenshot below (found in the HD3SS460 datashet pg.17 )?

note: SBU1 and SBU2 are crossed.

note: this is for pin assignment C and E not pin assignment D

Thanks

Jeff

Hi Jeff,

why SBU1 and SBU2 are crossed? I think crossing is needed if USB-C cable inserted with 180degree rotation - than we will have polarity event

Look, i have 2 USB-C MUXes like this:

Than, I have made connections of 2 ports like that:

In that case I am able to detect monitor (looks like AUX lines works OK - I could get parameters of the monitor) but i can't get video out. 

Also i have tried to solder wires directly from Port1_DP to Port2_DP - without MUX1, and situation is the same.

So, please confirm that I have to connect Lane 0 Source to Lane 3 Sink and so on.

I also have tried to connect Lanes like that: LN0 to LN0, LN1 to LN1, and so on.. But same result - I can detect Monitor and parameters of it at MacBook, but no video.

Also, do you know, LG UltraFine monitor, is it works in USB-C mode or only as Thunderbolt 3? I am afraid that it is not working due to that/

Hi Sergii,

I attached a word doc to answer your questions. Please let me know if I helped you solve your issue or you have any more questions!

port to port DP connections.docx

Thanks

Hi Jeff,

thanks a lot! Will try to check it right now.

Thanks for comment about USB 3.0 P/N swapping. It was done at TI board that we have - EVK TIDA-01243 ;) And than i found that USB 3.0 standard allows to swap P/N  signals (only between the pair RX or TX). I also found it somewhere at TI forum.

USB 3.0 part works OK in our project.

I will check video connection and back to you :)

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Best regards,

Sergii

Hi Jeff,
unfortunately - nothing changed. Video doesn't work.
MacBook detecting that monitor ids presented and show that everything is ok, but video is absent.
I have tried to check LG UltraFine monitor and Samsung 4k via usb-c to Display port cable - same results...
Only 1 monitor was connected at same time.
Any ideas?
Do you have any EVK that could pass video from USB-C to another USB-C?

Best regards,

Sergii

p.s. - PD IC configuration file

PD_PORT1_no_source_TI.zip

Hi Sergii,

Dont worry we will get this working. I attached a word doc with a few suggestions. Please let me know of any updates!

DP_debug_ideas_QA_e2e.docx

Thanks

Hi Jeff,
thanks for the answers,
some answers: I have tried to set "F" Pin assignment just for the test. It doesn't work without it too. I am using 2.12 config tool. So, i will try to update and check again. About Display Port signaling - there was also DP 1.3 there, and i've decided to try with "unspecified".
I will check my USB 3.1 lines again to understand what is wrong.
I already have communication between the MacBook and Monitor via my board (AUX data is OK, HPD signal available), so i have an issue in latest step - no video :)
Can you please provide a link to your "82 EVM" ?

Can you provide a links to schematics of that boards?
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Best regards,
Sergii

Hi Jeff,

any news? I found SCH and checked that I have correct schematic connection. Will order kits and proceed with them, looks like there are something wrong in configuration (at our board)

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Regards,

Sergii

Hi Sergii,

Sorry for the late reply.

The DP expansion board can be bought here:

www.ti.com/.../DP-EXPANSION-EVM expansion board&tisearch=Search-EN-Everything

If you think the issue is in the configuration I will ask my team to look into your project file. I will update you asap with anything we find.

Thanks

Hi Jeff,

yes, i already found that board and found that there are 2 different EVKs - for x82 and x86 ICs. We have x82 kits, without DP port.

We have ordered 2x x86 kits + DP expansion board to test solution with MacBook and LG monitor.

It will be good if your team will look into the project file.

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Best regards,

Sergii

Hi Sergii,

I just wanted to update you, I am still looking into your pjt file with the team. I noticed the pjt file you sent me does not have a low region included. Can you send me the low region bin that you are using the pjt file with?

note: When using the x86 EVM I had to change GPIO0,3,14 to 'plug event', 'AMSEL', and 'CC2 orientation' GPIO events respectively.

Thanks

Hi Jeff,
I got kits and already made some testing, unfortunately that doesn't work..
I have 2x TPS65986 kits + Display port expansion pack.
1 PCB configured to UFP (0010 configuration)
2nd PCB configured as DFP (1000 configuration)

MacBook is able to detect that monitor is connected, MacBook could see LG USB Audio, and could see LG monitor, but video is absent and MacBook became to work too slow...

_
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Regards,
Sergii

Hi Sergii,

To clarify, you are using only 1 EVM for the two additional tests?
What USB-C monitor did you use for additional test #1?  is that the same as the LG monitor?

- try using a different monitor

- try using a windows laptop.

- try using config ID 5 instead of ID4 for the UFP.

- You can also try to update or reinstall your graphics driver on your laptop.

I would like to see a lecroy PD trace of the failing case too.

Thanks

Hi Sergii,

Currently we are seeing something simiar to you. In the past this has worked with the ultrafineLG, the only difference now is the version of the tool and possibly the template. 

The laptop sees HPD and enters DP mode however no video. We are simply using one 86 connected to the type-C-monitor with a type-C to type-C cable, and the laptop connected to DP source expansion board with DP to DP mini cable. My next step is to probe GPIO0,3,14 to see whats going on. Also see if there any inconsistency with PD messaging. Theres some delay in testing because the type-C monitor I need to use has been occupied but I will stay late/early so I can use it. I will let you know the results later today or tommorrow.

Thanks

Hi Sergii,

I found this e2e post of a similar DP issue using LG type-C monitor, x982, and the HD3SS460. This may or may not help you so I will keep updating you of my progress with this issue.

Thanks

Hi Jeff,

thank you for the inputs. In my case TPS65982 + LG works OK)

So, i just need to pass video from 1 USB-C to 2nd USB-C)

Will wait an answer from you, thank you for the support.

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Best regards,

Sergii

Hi Jeff,

thank you for the update,
yes, i was able to do that too :) I have IBM PC with miniDisplay Port and it works OK with LG monitor.
But when 2 EVM PCBs connected together - i am not able to pass video from MAC to USB-C -> kit1 -> DP cable -> kit 2 -> USB-C -> LG monitor
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Best regards,
Sergii

Hi Sergii,

Is this block diagram correct?

I am unable to find a mini-DP to Type-C cable however I can order a DP female to male Type-C adapter.

Thanks

Hi Sergii,

I might have to obtain a LGultrafine monitor - let me ask my team for suggestion and I will let you know the update by the end of today.

Thanks,

Hi Jacob,

I am making device, where i need to be able to pass video from USB-C (macbook) to USB-C (LG monitor). We have TI USB HUB, with USB-C upstream to MacBook, and USB-C downstream to LG monitor. I got PCBs where everything is connected according to the guides, but we can't pass video. Than I have ordered 2kits, that were suggested by Jeff. And made tests.

Test setup was done according to Jeff's picture:

I am using MacBook Pro 2016 and LG UltraFine monitor, see below.

As you can see - Mac is detecting the monitor, detecting type of the monitor, but starting to work very slowly (I have detected that USB-C monitor changing HPD signal all the time - it was checked at EVK - with 5Hz frequency. So, 5 times during 1 second LG monitors says that it s connected and than disconnected). And video at LG is absent. I also have tried to connect kit with USB cable - in that case Mac is detecting USB HUB that is builded into the monitor. But still no video. I have tried all possible UFP/DFP configuration for the EVK by jumpers. And i didn't changed original FW at kits.

I really hope that you and Jeff will help me to get this working :)

Best regards,

Sergii

Hi Jeff,

ys, i need to connect 2 EVMs in this way because I need to pass video in our device from USB-C to USB-C ports.

When I am using EVMs in regular ways: USB-C to DP monitor or DP output to USB-C monitor - everything works OK.

I think that it is something with the protocol. Looks like MacBook is detecting the USB-C LG monitor via AUX lines and starting to work by using Thunderbolt protocol with it.

So, my guess, that there is something with the protocol there.

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Best regards,

Sergii

Hi Sergii,

YAY! great news! Thanks for your patience throughout and also thanks for letting me know the issue was the monitor.  

let me know if you have any more questions I would be glad to help you out :)

Thanks