i.MX8MP: false USB overcurrent event

Niebel-TQ — Fri, 22 Aug 2025 07:59:49 GMT

In a new design using i.MX8MP we use the USB1 (first instance) as USB 2.0 only interface. The USB 3.0 data lines are not connected. The port acts as a dual role port with cable detection (USB 2.0 Micro A/B). Device Role is working properly. Host Role initialisation fails with overcurrent events from Root Hub all the time.

To isolate the problem we tried to force Host Role by

set Host Role in device tree
remove cable detect logic (don't care for ID signal, muxed as GPIO)
force the USB power enable to always on per GPIO and disable port power control in glue logic (clear PORTPWR_EN in register USB_CTRL0)
Use the USB_OC# as GPIO pin

Everytime the port is initialized overcurrent event is signalled by Root Hub making Host Role unusable. In documentation there is no hint how to disable Overcurrent handling via register setting (this is possible in other i.MX CPU)

Is there anything we miss here? Thank you.

Re: i.MX8MP: false USB overcurrent event

Rita_Wang — Fri, 22 Aug 2025 08:38:53 GMT

Could you share us your hardware design to us, I mean your schematic? We need to check the hardware design first. Thanks

i.MX Processorsのトピックi.MX8MP: false USB overcurrent event

i.MX8MP: false USB overcurrent event

Re: i.MX8MP: false USB overcurrent event