imx8mp MIPI is abnormal at low temperatures

[Joshua2]

The MIPI configuration is as follows:
1）CSI1 @ 2LANE.
2) The sensor frequency is 600Mbps
3) The CPU temperature is 10 ° C.

We are currently facing a problem where it works normally at room temperature but is abnormal at low temperatures. The following is the log of opening debug for "imx8-mipi-csi2-sam. c"

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[ 547.189463] mxc-mipi-csi2.1: Frame End events: 17   (At low temperatures, it is 0)
[ 547.189469] mxc-mipi-csi2.1: Frame Start events: 18 （At low temperatures, it is 0）
[ 547.189474] mxc-mipi-csi2.1: Non-image data after odd frame events: 0
[ 547.189481] mxc-mipi-csi2.1: Non-image data before odd frame events: 0
[ 547.189487] mxc-mipi-csi2.1: Non-image data after even frame events: 0
[ 547.189494] mxc-mipi-csi2.1: Non-image data before even frame events: 0
[ 547.189501] mxc-mipi-csi2.1: Unknown Error events: 0
[ 547.189508] mxc-mipi-csi2.1: CRC Error events: 0
[ 547.189514] mxc-mipi-csi2.1: ECC Error events: 0
[ 547.189521] mxc-mipi-csi2.1: FIFO Overflow Error events: 0
[ 547.189528] mxc-mipi-csi2.1: Lost Frame End Error events: 0
[ 547.189534] mxc-mipi-csi2.1: Lost Frame Start Error events: 0
[ 547.189541] mxc-mipi-csi2.1: SOT Error events: 0

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By the way, imx8mp has 2 MIPIs, and the default configuration for the device tree is CSI0 at 500MHz and CSI1 at 266MHz. What is the difference between them?

Thanks,

Joshua

[joanxie]

1)how many boards do you get this low temperature issue?

2)By the way, imx8mp has 2 MIPIs, and the default configuration for the device tree is CSI0 at 500MHz and CSI1 at 266MHz. What is the difference between them?

> if you want to connect 4k@30 camera, you must use the mipi csi1, mipi csi2 couldn't handle it

[Joshua2]

Thank you very much for your reply.
1. There are a total of 10 boards, and 3 of them have this problem.
2.Does CSI2 support 4lane?

[joanxie]

1. There are a total of 10 boards, and 3 of them have this problem.

> did you do the ABA test?

2.Does CSI2 support 4lane?

>yes, imx8mp can support max 4 data lane

[Joshua2]

Thank you very much for your reply.
What is the ABA test?

[joanxie]

try to exchange the chip on the broken board with good board to check if this issue is still exist

[Joshua2]

Thank you for your reply!
Replacing the chip is quite difficult, and we haven't done it yet.
We will try to modify the mipi rate of the sensor to receive it.
2lanes, Both 500M and 700M are OK, but 600M is NG.
Is this related to clock frequency configuration? (clock frequency=<266000000>, default dts configuration)
Do I need to adjust the 'clock frequency' after replacing different sensors?
Can the MIPI reception of IMX8MP adapt to different MIPI rates?

Thanks,

Joshua

[joanxie]

if 500Mhz and 700Mhz can work, 600Mhz should be ok, what kind of issue do you get? do you mind sharing the different register dump between 700/500Mhz and 600Mhz? and other solution one you can try to change the hssettle value

[Joshua2]

500/600/700 only modified the speed of mipi, the other configurations are the same.
The current abnormal phenomenon is using the same camera configuration at 600MHz. Out of 10 devices, 3 were found to be abnormal at low temperatures.
What we want to know is how to configure the DTS of IMX8mp to match the mipi speed of different cameras?

[joanxie]

What we want to know is how to configure the DTS of IMX8mp to match the mipi speed of different cameras?

>as I mentioned before, you can change the hssettle for the different speed camera, and for the  SOT Error, I suggest that you can change the hssettle value, I don' t know what you set, you can change it to double check this issue