TDA4VM: how to config DSI display

Hi wu,

The first two changes are fine, but i am not sure about third change. The default code configures ub941 serializer and ub925 deserializer. Since you are changing deserializer to ub948, this needs to be properly configured.

Since lock itself is not getting detected, this issue is not related to DSI. The issue seems to be somewhere in SERDES. 

Regards,

Brijesh

HI TI:

    we had test 941 pattern mode. 941 -> FPDLINK-> 948-> LVDS->HDMI. from HDMI port ,we can see the color bar. it is OK.

    now we config DSI, we found DSI CLK is 400Mhz. but the resolution is 1280*800. from the code we found default DSI resolution only support 1280*800;

so i have two questions;

    1. could  the DSI resolution change to others? like 1080p 720p and so on.

    2.  the DSI CLK looks like wrong. the ring clk shoud be 1280*800*60*12/4/2 = 92.16Mhz. res:1280*800 fps:60 format:12bit YUV420. 4 DSI lanes. 2 DSL CLK edge. TXCLK_P and TXCLK_N .

    by the way can you give the ub948 configures or some advise reference?

    thanks very much.

Hi wu,

lock between SERDES is required even for color bar display, so if you are able to display color bar from ub941, then lock is established between SERDES. 

Yes, it can be changed by changing timing parameters and pixel clock. Please make sure that the lane speed is sufficient to carry this resolution. 

lane speed and pixel clock are two different inputs. 

Regards,

Brijesh

HI TI:

    now i find after TDA4VM power on 10s-15s，the DSI0_TXCLK_P pin measure about 450Mhz，and the I run ./vision_apps_init.sh，the clk pin has no change.from the log i found res is 1280*800,pixel clk is 82.17Mhz. why DSI clk has no change? DSI clk should be 246Mhz. how to change it? thanks 

Hi Wu,

By default driver sets up the lane rate to 870Mbps to 950Mbps, so if you are seeing 450MHz clock, it looks to be correct. 

Regards,

Brijesh

HI TI:

   can i change this dsi clk? how to change the default config?

Yes, it can be changed, by this needs some changes in the driver. Because it is currently fixed in the driver 

Rgds,

Brijesh

HI TI:

   now default code DSI is 2lane,1280*800. if i want to change DSI 4lane, how to change it? i do some changes for DSI 4lanes,but MIPI DSI data is always low,it has no data. 

Hi,

Can you try changes explained in below thread?

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1001574/tda4vm-whether-to-enable-dsi-continuous-clock-mode/3703503#3703503

Regards,

Brijesh

HI TI：

    now it can display in DSI 4lanes. but when SOC output is RAW12 YUV420 video format , display is grey white, it can't display color video. pattern color mode is OK with extern DSI CLK extern timing. so can you give some suggest to solve it ? thanks a lot

Sorry, did not get it. What's the error you are seeing? What is the input format you are using? Is it RAW12 or YUV420? 

Where pattern color is enabled? 

Regards,

Brijesh

HI TI：

    from HDMI output，i see the pictures is black white and it is blurry. the video format input is 12bit YUV420. 

when i set 0x64 0x15 , 0X65 0X00, 0x56 0x00,i can see the color bar picture.

so i want to ask why when in video mode, it can't display color picture? 

Hi Wu,

Can you first dump/save one frame, which is sent for the display and analyze offline to make sure that the input is correct? Display supports YUV420 12bit format, but how do you generate it? Have you taken care of pitch correctly? Also 12bit data would be stored in 16bit container. so each component will take 2 bytes. Is this taken care in the application? 

If possible, can you share your example?

Regards,

Brijesh

HI TI：

    we use run_app_multi_cam.sh demo to generate graph. now we change the demo src code to generate RGB888 24bit picture. and we dump buf from csi demo code we found it is normal. but we find from HDMI it is also grainy screen. can you give some advise? thanks.

     CAM_CAPTURE->DSI->UB941->FPDLINK->UB948->LVDS->HDMI->display.  

  we capture buffer from CAM_CAPTURE output.

 we doubt that is any modify with DSI config. because when ub941 the Pattern Generator uses external video timing and set Bridge Clocking Mode 00: DSI Reference Clock Mode,it can  normal display. 

Hi Wu,

I think you could even enable color bar test pattern in the VP of the DSS. Can you try it and see if color bar output is correct on DSI?

If it is, it will confirm that artifacts are coming from video pipeline. 

To Enable color bar, set bit1 in DSSx_OVR_CONFIG register, where x is overlay being used for the DSI output.

Rgds,

Brijesh

HI TI:

    I set bit1 in DSSx_OVR_CONFIG register with overlayRegs 2. it can output Colorbar. 

   i don't understand "it will confirm that artifacts are coming from video pipeline"? do you mean pipeId need change?  how to changeit ?

Hi Wu,

Yes, it means DSI output is as such fine, but the artifacts are coming from video pipeline. 

How many pipelines are yo using? What is the input/output format of the video pipelines? 

Which usecase are you using in vision apps to check DSI output?

Regards,

Brijesh

HI TI：

    only one pipelines using. disp_params.pipeId = 2; I use ./run_app_multi_cam.sh to check DSI output. the camera output compress images are 24bit RGB888 format. i can't find is there any setting for input/output format of the video pipeline. can you find it? thanks

Hi Wu,

the default output resolution from multi-camera is 1080p, but the supported resolution for DSI is 1280x800. Have you made changes in the resolution? 

Regards,

Brijesh

HI TI:

    yes , i have change compress image resolution to 1280*800.

But how do you compress resolution it to 1280x800? 

Where did you change output resolution to 1280x800?

Rgds,

Brijesh

Hi,

You could keep input resolution of DSS to 1080p and then using DSS inline scalar, downscale it to 1280x800 resolution (set outWidth/outHeight to 1280x800). This will work fine. Can you try it out? 

Regards,

Brijesh

HI TI:

    default DSI resolution is 1280*800. and we have change CSI camera output code downscale to 1280*800. we have test it use eDP port and see screen display 1280*800. so i think resolution have no problem. you said input/output format of the video pipeline need to set? i can't find it. now we think it is video format problem.

Hi Wu,

Multi-camera example uses SWMS link to create mosaic of camera frames, the output from swms node is in 1080p resolution by default. So have you changed this resolution also to 1280x800?

If this is changed, have you also updated position and output size of each camera frame?

Instead of making these changes, i would suggest to keep mosaic size to 1080p and then using dss scalar, downscale 1080o to 1280x800 resolution.

Regards,

Brijesh

HI TI:

   yes,we have using dss scalar, downscale 1080o to 1280x800 resolution. because we dump the output buffer is 1280*800. so i think resolution has no problem

ok, can you please save mosaic output and view it offline for analysis? I want to first make sure that the input to the DSS is correct. 

Rgds,

Brijesh

out010_1280x800.rar

Yes, something is really wrong with the format. The image you shared is in YUV422 format, but SWMS does not support yuv422 format, it supports only YUV420 format. Which node are you using for YUV422 SWMS? Is the same format also configured in DSS Node? 

HI TI:

 J721EXCPXEVM: J721EXCPXEVM video camera driver (ds960+ds933 4 lanes) - Processors forum - Processors - TI E2E support forums

we have change camera output to YUV420 format. it is my colleague do the change like above. you said i shared .rar is YUV422 format. i don't  know why you said it is YUV422. i  use 7yuv software open it, and i find it is RGB888 format.  this is our flow chart

Hi,

ok understand.

Just one question, how do you change msc scaler output from 1280x800 YUV420/NV12 to 1280x800 RGB format? 

Essentially, what is input to the DSS? Is it 1280x800 NV12 or 1280x800 RGB format? 

Rgds,

Brijesh

HI TI:

     we add an openVx node do this change .it can convert YUV  to RGB. and then sendback RGB format image to DSS.  so DSS input should be 1280*800 RGB format. we have dump the sendback buffer. the buffer is .rar file. do you mean is any change in DSS node? and DSS node default is NV12 format? 

Hi,

I am also now doubting on the format that has been give to DSS. 

As such YUV420 format is supported, so can you please try removing YUV420_to_RGB node and connect 1280x800 NV12 output of the scalar directly to the display?

Regards,

Brijesh

HI TI：

    because default code is YUV420 NV12 format ,we have test it  display grainy screen. so we try change YUV420 to RGB888 format. but it also has problem. now we don't konw how to solve it. 

Hi Wu,

Can you please keep the output image as NV12 and show me the display output? 

We have 1280x800 resolution working on the DSI display, so NV12 image should work as it is. 

Regards,

Brijesh