It is a driver bug. It allows too low an HMAX value to be set (control V4L2_CID_HBLANK), and that causes a FIFO underflow in the sensor.
The numbers at https://github.com/raspberrypi/linux/bl ... 415.c#L525 are wrong.
Even in that state I get images from the sensor, but the underflow results in a diagonal stripe effect as every line is too short.
Quick fix of copying in the values from ".lane_rate = 720000000" works.
Now to work out what the correct numbers are....
If Waveshare have changed the oscillator, I might make using it easier in the overlay too.
The numbers at https://github.com/raspberrypi/linux/bl ... 415.c#L525 are wrong.
Even in that state I get images from the sensor, but the underflow results in a diagonal stripe effect as every line is too short.
Quick fix of copying in the values from ".lane_rate = 720000000" works.
Now to work out what the correct numbers are....
If Waveshare have changed the oscillator, I might make using it easier in the overlay too.
Statistics: Posted by 6by9 — Mon Mar 31, 2025 1:27 pm