TDA4VM: How to use DSS writeback feature in Linux

Tiancheng Zhang

Part Number: TDA4VM

Hi, TI Experts

I'm working on Linux SDK 8.4, I want to use the DSS writeback feature in Linux to pass the display content to CSI-TX.
But I found that DSS writeback feature has not been supported in Linux from SDK 8.0 release:

SDK release note:

and this thread:

TDA4VM: TDA4VM: Output video on CSI TX interface

Could you please teach me:
1. Why is DSS writeback feature removed from Linux?
2. Is it possible to porting Linux DSS writeback feature from SDK 7.3 to 8.4?

BR,

Tiancheng

over 2 years ago

+1 Brijesh Jadav over 2 years ago

TI__Guru**** 475745 points

Hi Tiancheng,

DSS Writeback path in Linux driver was available as mix of V4L2 and DRM framework, not a cleaner way and was not official supported. Also there are other ways of doing what DSS WB path can support. So this path is removed from the Linux kernel.

Yes, if you require, you could port it, but we will not be able to support much.

Regards,

Brijesh

0 Tiancheng Zhang over 2 years ago in reply to Brijesh Jadav

Prodigy 190 points

Hi Brijesh

Thank you.

What is the other way to support DDS WB path can support?

I created another thread later to describe our DDS application scenario in detail. We are faced with many problems and hope to get your help, thank you.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1178459/tda4vm-using-dss-for-image-blending-and-then-output-via-csi-tx

0 Brijesh Jadav over 2 years ago in reply to Tiancheng Zhang

TI__Guru**** 475745 points

Hi Tiancheng Zhang,

Did not get your question, i think we already discussed about how you could support DSS WB path in your application on the other thread, Let me know what issue you are facing..

I would suggest to continue the discussion on one thread and closing other threads..

Regards,

Brijesh

0 Tiancheng Zhang over 2 years ago in reply to Brijesh Jadav

Prodigy 190 points

Hi Brijesh

I will close this thread. Let's continue to discuss it in the other thread.

Thank you for always supporting.

BRs

Tiancheng

Processors

Processors forum

TDA4VM: How to use DSS writeback feature in Linux