TDA4VM: Problem of DP output on screens

Hua Jianxiong

Part Number: TDA4VM

Hi TI experts,

We are using TDA4 board to do ISP tunning with sdk 7.3. Recently we have met a problem on DP output.

The problem are decribed below:

If we connect TDA4 board with a DP screen (manufactured in 2019) using a DP cable, the display on screen is normal with no problem. But if we connect the TDA4 with another DP screen (manufactured in 2021), the screen cannot find any DP signal. And we are very certain that the two tested screens can work well if connects to a PC.

Do you know know the reasons why TDA4 supports some DP screens but not surports other DP screens?

Best regards,

Jianxiong Hua

over 3 years ago

0 Brijesh Jadav over 3 years ago

TI__Guru**** 477995 points

Hi Hua Jianxiong,

Are you sure that both the displays support standard 1080p 60fps resolution? Can you please check the timing information of both the display and confirm if they support these timing information?

Regards,

Brijesh

0 Hua Jianxiong over 3 years ago in reply to Brijesh Jadav

Intellectual 410 points

Hi, Brijesh,

I'm sure that both the displays support standard 1080 60fps resolution.

As for the timing information, I'm not sure how to check it for the display. But is it possible that standard DP devices have different timing information?

Regards,

Jianxiong

0 Brijesh Jadav over 3 years ago in reply to Hua Jianxiong

TI__Guru**** 477995 points

Hi Jianxiong,

ok, can you please do one experiment? Can you keep display disconnected during boot and connect it later on and see if it detects the signal correctly?

Regards,

Brijesh

0 Hua Jianxiong over 3 years ago in reply to Brijesh Jadav

Intellectual 410 points

Hi Brijesh,

I have conducted the experiment, and it still cannot detect the signals for Screen 2. In addition, I even successfully run single_app and can save images through DCC tool, but at this time the DP signals still cannot be detected when I connect DP to Screen 2.

But if I use Screen 1(another screen), everything is OK. Do you know what causes this phenomon?

Could you recommend some types of Screen that is supported by TDA4?

Best regards,

Jianxiong

0 Brijesh Jadav over 3 years ago in reply to Hua Jianxiong

TI__Guru**** 477995 points

Hi Hua Jianxiong,

I think you are using SDK7.3. In this case, can you please apply the patches i had shared at the end of below ticket?

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1031275/faq-processor-sdk-j721e-edp-firmware-responds-wrongly-to-some-messages-and-thus-causes-display-incompatibility

Regards,

Brijesh

0 Hua Jianxiong over 3 years ago in reply to Brijesh Jadav

Intellectual 410 points

Hi Brijesh,

Thanks for providing the patch to me, and the problem of display failure on some DP screens has been solved after apply the patch.

But the DP output seems not supporting conversion of DP signal to HDMI. Is it possible for TDA4 to surpport DP converting to HDMI signal?

Regards,

Jianxiong

0 Brijesh Jadav over 3 years ago in reply to Hua Jianxiong

TI__Guru**** 477995 points

Hi Hua Jianxiong,

Do you mean on EVM? If you have external active DP to HDMI converter, it can be supported on EVM. You would just to disable ETHFW, rebuild vision apps and rerun the usecase with DP output.

Regards,

Brijesh

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TDA4VM: Problem of DP output on screens