Issue with standalone DisplayID

[daffenen]

- Window 10
- RTX3070
- DP 1.4

Hi
I'm working as an engineer in display field.
Our device is kinda aging device for panel, it has dp input and Vby1 output.

So if I set edid and connect with PC, PC recognize it as a monitor.

It works well with EDID but higher resolutions(5k, dqhd etc) are coming out so EDID doesn't work anymore.

I've already used DisplayID Extension block but I guess it cannot cover all kind of GPU(espacially AMD and Intel).
Some of my clients' GPU doesn't work with DisplayID extension block.

So I'm trying to apply standalone DisplayID 2.0 and mostly, it worked.

I could change the resolution, refresh rate and also the name of the monitor.

But I got a problem and this it what I wanna ask you.
Even if I changed the model, the last resolution still remain in new model.
It's stacking everytime I change the model.
(for example,If I set DisplayID to 4K at the first time and although I changed it to 5k, 4K is still remaining and it is the default resolution)
After I reset with CRU and connect again, finally they are gone.
And also our device was turned into Non-PnP monitor from PnP monitor

I already tried changing manufacturer ID, product ID, serial number of DisplayID but nothing worked.

It looks like PC recognize all models as one model.
Anyone knows about this issue?

[ToastyX]

CRU doesn't support standalone DisplayID, only DisplayID extension blocks, and CRU currently doesn't support adding or editing most data blocks with DisplayID.

DisplayID extension blocks should be supported by all the major GPUs including AMD and Intel, but old GPUs with old drivers will not recognize DisplayID because no monitors used them at the time.

Certain higher resolutions such as 5120x2160 and 7680x4320 can be added as TV resolutions in a CTA-861 extension block, but that also requires a newer GPU and driver.

The stacking problem is something I never heard of happening and sounds like a GPU-specific driver bug, like it's caching the resolutions and not reloading the EDID correctly.

[daffenen]

(04-13-2023 01:03 AM)ToastyX Wrote:  CRU doesn't support standalone DisplayID, only DisplayID extension blocks, and CRU currently doesn't support adding or editing most data blocks with DisplayID.

DisplayID extension blocks should be supported by all the major GPUs including AMD and Intel, but old GPUs with old drivers will not recognize DisplayID because no monitors used them at the time.

Certain higher resolutions such as 5120x2160 and 7680x4320 can be added as TV resolutions in a CTA-861 extension block, but that also requires a newer GPU and driver.

The stacking problem is something I never heard of happening and sounds like a GPU-specific driver bug, like it's caching the resolutions and not reloading the EDID correctly.

Thanks for your reply!

Yes I know that CRU deosen't support standalone DisplayID so I just use it when I reset and restart. We write EDID and DisplayID manually though our software.

I thought it's just a problem of old GPUs but it happens to new GPUs like Pro W6600.
It supports 8K and 5K. I know it's not an usuall model like other GPUs for gaming.
But I think it doesn't mean that it cannot support extension blocks.

I checked this issue with W6600, W5100, Intel XE Iris. don't know the reason but they cannot read the extension block.

yes also there is CTA-861 but our device is needed to cover more resolution like 5120x1440 so I couldn't use it.

Sadly there is no one who knows about staking issue... I hope I can solve it in future. I'll keep checking this forum. Thank you ToastyX