Touchpad testing.

[Mitch Bradley]

By the way, the "aggressive flow control" that I alluded to in my last
message is not what is shown on the picture. The picture shows a modest,
no-problem amount of flow control on the order of hundreds of *micro*seconds

The "aggressive flow control" that results from the queue filling up
hundreds of *milli* seconds. If the software is not draining the queue
fast enough, that would explain the observed symptoms.