We have an own developed display solution based on the CM3 module. We did not have any problems during the development, everything was fine. Now we have recently got the first production batch (100pcs) from the manufacturer and each device crashed randomly (kernel panic or just hang completely). It's like as the RAM to become corrupted.
After a week of investigation (components, power supply, EMI, manufacturing quality, etc.) we found that the only difference that the CM3 module we used for the development was purchased from the RS while the batch was purchased from the Farnell. The RS module was made in the UK, the Farnell module was made in PRC. Visually, it seems the quality of the PCB is the only difference.
Finally we reduced the RAM and ARM clock as one last try (sdram_freq=400, arm_freq=1000) and this solves the problem! Looks like it's a signal integrity problem in the Farnell's CM3 modules (maybe inadequate material used for the PCB). The serial numbers on our Farnell modules are:
Has anyone else experienced this problem?