IMX6 mipi CSI2 sensor display on HDMI issue

[eason-tang]

Hello :

I am porting a image sensor with mipi csi2 interface on imx6qp platform.

Now my image sensor（YUV422+VC0）data could display on HDMI1.

But my problem is there is a vertical line on HDMI screen like attatchment.

My analyze data workflow:

Sensor -> mipi D-phy csi2 TX -> mipi D-phy csi2 RX (imx6 side) -> memory -> display HDMI.

So i guess the vertical line is not generated by sensor, it maybe a mismatch or problem in mipi D-phy csi2 RX (imx6 side) -> memory .

Perhapes a issue with mismatch mipi RX freqence or a mistake buffer control .

Did anyone have faced this issue ?

How to analyze this issue ?

Best Regards.

Qingcai.

[dirkbender]

Hello,

I have the same vertical Line on the HDMI Screen. The Line appears if i go over approx 750 Mbps (4 Lane) on the CSI-2 Port.

The data workflow is the same as by Qingcai.

At the moment I have no idea why this is happen. My guess is, that the i.MX6 can not handle this amount of data. I Checked it on a Quad and a Quad Plus.

I work also with FPD-Link III and where I need the 800 Mbps. 

Are where any Idea?

[Rita_Wang]

iMX6DQ TP2854 MIPI CSI2 720P HD-TVI camera surround view solution for Linux BSP 

https://community.nxp.com/docs/DOC-328548 

These maybe do help for you.

[eason-tang · Accepted solution]

Hi b45499‌:

I have resolved my problem.

First of all, thank you for your support.

Share my trouble shoot experiences to others:

1st:   Configure your sensor or de-serializer to output ColorBar test pattern.

2rd:  With ColorBar test pattern output ,you could anaylize the problem is or not Sensor issue.

3th:   I also found the vertical line with ColorBar test pattern output.

So it maybe the HOST mipi-csi2-RX mismatch.

4th:   I decreased mipi-csi2-TX(Sensor module) clock and decreased mipi-csi2-RX(HOST) clock from 1.6Gbps to 400Mbps .

Then the vertical line disappeared.

Best Regard

Qingcai

[Rita_Wang]

Got it. Thanks for your sharing.

[Rita_Wang]

Good news~~

[eason-tang]

Hi b45499‌:

I have another question about this topic.

Now i decreased mipi-csi2-TX(Sensor module) clock and decreased mipi-csi2-RX(HOST) clock ,then the vertical line disappeared.
But i reviewed some documents about imx6 MIPI CSI2 spec.

The maximum bandwidth of the interface is:
• 200 MHz for a 4-lane configuration (800 Mb/s/lane, 400 MB/s)

Does it mean the maxim rate of imx6 is 800Mb/s per lane with 4-lane ?

In my project ,i used TIUB964 de-serilizer 4-lane output YUV422 data with 800 Mbps serial rate .

So my question is Why could appeare the vertical line with the same 800Mbps?

Could imx6 mipi-csi2-RX receive the mipi clock larger than 800Mbs/lane with 4-lane ?How to modify it ?

Best Regard

Qingcai

[eason-tang]

Hi b45499‌:

I have reviewed these Topic.But i think my question is not in these Topic.

Today, I do this test ahout my question .

1st: I dumped YUV data to a local file and opened the file by YUV analyze tool.

I could see the vertical issue line like mistake data in the picture.

2rd: I replaced imx6 device with my internal FPGA board, and showed YUV data in pc tool with the same sensor settings.

I could not see the vertical issue line.

So I think the mistake maybe come from MIPI-CSI2-RX .Right ?

Could you give me more suggestions?

Best Regards

Qingcai

[eason-tang]

Hi:

I have some tests on it.

1st : I moved my sensor to another angles. 90 degree,180 degree,270 degree or other scenes.

The vertical issue always have and does not change anymore;

So this is not a sensor issue .

2rd: I changed other sensors (2-lane YUV422 1280x720) to display on the same platform .

There is not any issues on screen ,no vertical lines.

So the hardware environment is OK.HDMI device or mipi D-phy RX module .

Best Regards.

Qingcai