As a final note, I have found that the Samsung tablet will draw an extra 0.7A if charged via the TPS2511 port, compared to being charged via the port which had D+ and D- shorted.
This is a surprising result, and probably means they are making use of this mode
compared to this much more standard mode for non-Apple chargers
The simple “D+ to D- shorted” mode does however seem to work 100% reliably for all the non-Apple stuff I have. It may not charge at the max possible speed but it will always charge.
For reference, Apple devices use one of these two and if you don’t do that, you get a very unsatisfactory result (usually zero charge unless the device is turned off)
It is difficult to get good data because all these devices vary their charging currents wildly according to state of charge, internal current draw (screen brightness, etc) and who knows what else.
