(11-25-2019, 03:07 PM)ElektromAn Wrote:(11-25-2019, 04:54 AM)Luke Wrote: The suspicion is that this has to do with PD negotiation failing when the device is powered off. This results in slow standard USB charging.USB-C PD is handled in the (running) kernel
driver source
drivers/usb/typec/tcpm/fusb302.c
I've been testing a variety of USB-C chargers combined with an AC power meter (much quicker the observing the gradient),
I'm seeing wildly divergent behaviour:
1. A system that is off will always draw ~2.5W (e.g. 500mA at 5V)
2. Connected to a modern multi-charger type A socket via a USB2.0 cable the PBP draws 10W
3. As #2 but with a USB3.0 cable the PBP draws 13W
4. Connected via a Lenovo 45W laptop charger the PBP draws 15W
5. Connected via an alternative 45W type C to type C charger the PBP draws 2.5W
All but #2 of the above is seen in both 4.4 vendor kernel and mainline (with Tobias' patches). I've only tested #2 using mainline.
