If your use case is only as a gadget that have USB ports that output a maximum of 15W, I think you will find that by adding:
PSU_MAX_CURRENT=3000
to your EEPROM, that the devices will boot as OTG gadgets every single time. Since the max output on a USB-C port on a Mac device (excluding iPads) is 15W from what I understand, the only limitations would be if you are also using the official Pi power supply to boot these CM5 boards on occasion and need to attach more current heavy devices to their USB3 ports. The above assumes any setup where you plan to power the Pi device over the USB-C port. Your PoE board seems to circumvent this problem.
My own experience is similar to yours, in that I have serious problems getting PD to play nice with proper negotiation of device/host status. By setting max current as above, it skips the PD initialization process which then allows the proper role negotiation to occur.
If you need more power than 15W you would need to design an external hub that establishes the proper data device/host relationship separately from providing 5V/5A PD power to the CM5.
Do the Windows machines that work even have PD usb ports? If not, then that would explain why they work without issue.
PSU_MAX_CURRENT=3000
to your EEPROM, that the devices will boot as OTG gadgets every single time. Since the max output on a USB-C port on a Mac device (excluding iPads) is 15W from what I understand, the only limitations would be if you are also using the official Pi power supply to boot these CM5 boards on occasion and need to attach more current heavy devices to their USB3 ports. The above assumes any setup where you plan to power the Pi device over the USB-C port. Your PoE board seems to circumvent this problem.
My own experience is similar to yours, in that I have serious problems getting PD to play nice with proper negotiation of device/host status. By setting max current as above, it skips the PD initialization process which then allows the proper role negotiation to occur.
If you need more power than 15W you would need to design an external hub that establishes the proper data device/host relationship separately from providing 5V/5A PD power to the CM5.
Do the Windows machines that work even have PD usb ports? If not, then that would explain why they work without issue.
Statistics: Posted by ChipChop — Thu Apr 24, 2025 10:15 pm