Sorry, but I can't seem to stop sticking my naive nose into this.

Isn't the n800 considered a "dumb" USB device? By "dumb," I mean that the hardware and the software (pre n810 kernel?) of an n800 knows nothing about USB OTG or USB charging.

If the above is true, and USB hardware and software is supposed to be backwards compatibile, I find it hard to believe that the USB chips are gonna try and be too smart. What I mean is, isn't it likely that the isp1707 and/or the TWL4030 are suppose to work in a scenario with two "dumb" USB devices?

Again, if the above is true, the hardware shouldn't care about what role the device it's in is playing. My n800's battery can power a USB music card and a pair of usb speakers at the same time!

So, once again, I think it's all about the software. Except this time, let's forget about the Beagleboard, let's make it all about the n800 and why it works. I realize there are crazy changes between 2.6.21 and 2.6.28, but the USB spec for "dumb" devices hasn't changed at all.

So, I agree with blue_led, let's turn of charger detection and roll back the n900 to the "dumb" USB device that it is. But looking too closely at the Fremantle USB kernel/driver code is muddying the waters, in my opinion. Quite frankly, that might be the last code you want to look at. Or at least do a diff with the 2.6.28 or the 2.6.27 baselines.