We are developing a custom board basing i.MX8MQ processor, we built 3 boards with the same Hardware configuration.
One of our boards started to log a "Wait for A2 ACK" message on boot and keep logging and not continuing the boot sequence. This board worked fine for several booting until this problem accrued.
All the rest of the boards are continuing to work fine.
What is A2 ACK means, and what is it related to?
(Attached a boot log)
If this is still relevant, this error may be caused by the DP.
By the log I see that you're using variscite Android configuration, could you try with a more recent version, asking in there would be a good idea as well.
Also, you may try with the workaround shared here: