**** BEGIN LOGGING AT Fri Jul 15 02:59:58 2016 Jul 15 05:02:47 >>find out from the USB PHY what type of cable is attached and report this to the battery charger<< check! done by charger chip w/o sw involvement Jul 15 05:04:19 >>detect when the power supply is questionable during boot, and limit activation of components until that is resolved<< check! doesn't apply since device is battery buffered Jul 15 05:16:35 however for charging deep discharged battery the bootloader should postpone booting linux as well as enabling *any* subsystems (except charger) until battery has reached a voltage level quite a few 100s of mV above system blackout voltage, by letting charger do its job of autonomous charging aka "emergency charging". The latter being the cure for the otherwise quite disastrous deadlock of "system can't charge since doesn't boot, Jul 15 05:16:37 can't boot since doesn't charge" Jul 15 05:18:13 Nokia N900 signals emergency charging by constant yellow indicator light Jul 15 05:18:29 on a hw level Jul 15 05:19:06 pabs3: many thanks for this link! Jul 15 05:26:46 >>The relationship between the EXTCON_USB* and EXTCON_CHG_USB_* cable types seems confused.<< I don't see any confusion there. #define EXTCON_USB 1 most likely means there's a peripheral type plug plugged in (ID pin floating) while define EXTCON_USB_HOST 2 most likely means host type plug with ID pin grounded Jul 15 05:27:48 both are orthogonal to all but one charger signal method **** ENDING LOGGING AT Sat Jul 16 02:59:58 2016