Important Fix
Ivport Raspberry Pi Camera Module Multiplexer is nascent product that may have some missings and limitations because of design, manufacturing and RPi's closed source video core libraries.
There is one important feedback from Michael M. Hoyer. He claimed that CSI connector's pin 11 (CAM_GPIO pin) should be connected for Ivport's working properly. Otherwise capturing may not be possible over Ivport after 2-3 capturing.
It was unintended design failure at development milestone but Ivport was working well even without pin 11 is connected. Development milestone failure was migrated to production of revision 1. But after production, longer duration (> 5 minutes) video switching tests showed that signal of camera is lost some minutes later.
Therefore 4 Camera Module CSI connectors' pin 11 is not connected to Input CSI connector's pin 11. It may cause random errors such as below;
mmal: Received unexpected camera control callback event, 0x4f525245
Error exists so because camera shutdowns ownself and can not capture image any more than three or any longer duration video switching than 5 minutes without that pin is connected.
Fixing this issue can be applied by below modifications;
Primary Fix; Connection between top layer's INPUT, CAM1 and CAM3 connectors' pin 11.
Alternative Fix; Connection between CSI Connectors of Camera Modules' Pin 11 and Pin 15
Primary Fix; Connection between top layer's CAM3, bottom layer's CAM2 and CAM4 connectors' pin 11.
Alternative Fix; Connection between CSI Connectors of Camera Modules' Pin 11 and Pin 15
Note: This issue will be fixed as soon as possible at production revision 2.