TDA4VM: csitx input 3840*1300 yuv422 with 30fps,but csitx output only in 15fps speed, can't speed up

Hi,

But the lane speed that you are configuring above is just 640Mbps. Can you please try increasing this lane band speed? 

Regards,

Brijesh

hi ti

   Thanks for your reply. 640Mbps is enough to transmit this amount of data. How much more dummy data will csitx increase compared to the input image data? How much data will the output of CSITx increase compared to the input data?

is the below setting about this？

prms->instCfg[loopCnt].vBlank = 22U;
prms->instCfg[loopCnt].hBlank = 40U;
prms->instCfg[loopCnt].startDelayPeriod = 40U;

Hi,

Ok, for this resolution, it requires 3740x1300x16x30 ~= 2.4Gbps minimum lane speed. I think there is an open issue in drivers that CSITX lane speed requires to be double, otherwise we get less fps. So can you first check increasing lane speed?

Regards,

Brijesh

hi Brijesh

    Ok, for this resolution, it requires 3740x1300x16x30 ~= 2.4Gbps minimum lane speed. I think there is an open issue in drivers that CSITX lane speed requires to be double, otherwise we get less fps. So can you first check increasing lane speed?

            -------------------> Normally, 640MBPS can fully transmit this data, but due to known issues with csitx, does this rate need to be doubled? So I need to set the speed to 1280mbps?

                I set the speed to 1000Mbps~1200Mbps, CSITX can output the data with 30FPS.But, there is an issue that the speed  exceeds the bandwidth of the serializer, so the serializer is unable to receive data properly.

       Is there any patch can solve the open issue?

Hi phoenix,

This issue is still under debug and no solution yet. 

https://sir.ext.ti.com/jira/browse/EXT_EP-11038

Instead of trying directly 1000Mbps lane speed, can you try one of 690, 770, 870 or 950Mbps and see if it helps? 

Regards,

Brijesh

hi Brijesh

    I have tryingn many lane speed,only the speed set to upper than 1000mbps csitx will output 30fps, otherwise, the output frame will lower than 30.

    And i have two questions:

   1.In fact, our project will eventually adopt the TDA4-AL platform. Does TDA4-AL have this issue?

   2.How much dummy data that will be added by CSITx ? How many data will increased  between output and  input of csitx node?

Hi phoenix,

Yes, TDA4AL also has this issue. 

All i can suggest now is to keep lane speed 2 times that required lane speed.. This will give correct fps.. 

Regards,

Brijesh

hi Brijesh

     OK, thanks. Could you give me some help with another question?

     How much dummy data that will be added by CSITx ? How many data will increased  between output and  input of csitx node?

Hi phoenix,

I dont think we need to add dummy data. With this change, the data will be sent out in 30fps. There is no need to add dummy data.. 

Regards,

Brijesh

Hi Brijesh

    Ok.Thanks a lot for your help!