Zynq UltraScale+ Live Video Input/Output

[koolscooby]

Hi All, 

The DisplayPort Subsystem has live vide input and output ports from the PL for enabling live video overlays/previews. I have successfully got the HSYNC and VSYNC to toggle (on the live video output) but I can't get a framebuffer to output any pixel data to the live video pixel output. I am not using the DisplayPort Source Controller. Here is the path that we want to use: 

The PL has a parallel TFT LCD connected. We have verified with an ILA in the PL that only HSYNC/VSYNC toggle. 

Any advice? Has anyone successfully gotten the Blended Video to PL to work?

[florentw]

Hi @koolscooby,

Sorry you had no response when you have written this post. I missed this thread.

Do you have any updates on this?

In case you still have issues:

Are you trying to use both the live input and output? Do you have any output on the DP controller?

Best Regards,

Florent

[koolscooby]

Hi @florentw,

Thanks for the followup. We were NOT using DisplayPort on the GTR(s). We got this to work by commenting some lines out of the DP/DRM drivers and loading them anyway. It's still not clear how much of the DP/DRM subsystem driver(s) are required to enable the functionality - but we did get something to work. It would be great if those driver(s) had a device tree flag for "live-vid-only" or something. 

In our use case, we were only trying to use the live video output from a linux framebuffer - but I could see where taking live video input and having alpha blending, etc - would be a useful and valid use case. 

Best, 

Brad

[florentw]

Hi @koolscooby,

Yes as far as I know, the current Xilinx driver does not support live output only so modifying the driver is probably the right way to go. It might be implemented later

Regards,

Florent

[radimsosty]

Hello @koolscooby,

Could you share the changes you made in DP/DRM drivers, please? I'm struggling with the similar problem.

Thanks,

Radim

[jdefields]

@koolscooby, @florentw,

Can we please get an elaborated response on this?  This is highly demanded feature, and needs to be fleshed out.

[ema1905]

Could you share your DP/DRM subsystem driver modifications?
Thank you