Link frequency is the clock frequency on the CSI2 clock lane. The log message "Using a link rate of X Mbps" is the data rate per data lane, not overall, so is link frequency x 2.
If you have measured a clock rate of 192MHz, then that is what the V4L2_CID_LINK_FREQUENCY should advertise, and the CFE log message should say 384Mbps.
Read up about the termination of MIPI D-PHY, and how they should be implemented in LP and HS modes. https://download.tek.com/document/61W_25772_0_HR.pdf is a good intro.
It sounds like your device is running in continuous clock mode.
When Unicam powers down it drops the terminations, hence distortion, but enables them when powered up.
It sounds like Pi5 is never engaging termination, probably as it's still waiting for a LP to HS transition.
We had looked at a clock mode related issue in https://github.com/raspberrypi/linux/pull/6705 recently, but haven't fully progressed it.
You say it's been going on for two months, but the radio silence has been from your side. I'd responded to your posts of 5th Feb on the same day. We will investigate where there is something we can do, but it requires information from the reporter.
If you have measured a clock rate of 192MHz, then that is what the V4L2_CID_LINK_FREQUENCY should advertise, and the CFE log message should say 384Mbps.
Read up about the termination of MIPI D-PHY, and how they should be implemented in LP and HS modes. https://download.tek.com/document/61W_25772_0_HR.pdf is a good intro.
It sounds like your device is running in continuous clock mode.
When Unicam powers down it drops the terminations, hence distortion, but enables them when powered up.
It sounds like Pi5 is never engaging termination, probably as it's still waiting for a LP to HS transition.
We had looked at a clock mode related issue in https://github.com/raspberrypi/linux/pull/6705 recently, but haven't fully progressed it.
You say it's been going on for two months, but the radio silence has been from your side. I'd responded to your posts of 5th Feb on the same day. We will investigate where there is something we can do, but it requires information from the reporter.
Statistics: Posted by 6by9 — Wed Mar 19, 2025 12:32 pm