I have a board, using an i.MX6DL. The board has 2 USB ports (P75 and P76). The first port, P75, is fed from the i.MX6's "USB OTG" pins, and the second port, P76, uses the i.MX6's USB_H1 pins. Both are supposed to be used as standard USB Host devices.
When using the ports, in U-Boot, both seem to be fully functional. I can see USB devices plugged in (via `usb tree`) and I can view the contents of the USB devices (via `fatls USB 0` and `fatls USB 1`). So clearly there is no hardware issue here.
Once I boot to the kernel, P76 still works as expected, but P75 shows no reaction at all when any USB device it plugged in.
One of my USB is a flash drive with a LED on it. The LED lights up when I plug it in to P75. Thus it would appear that the USB port is indeed powered still, but the kernel doesn't give any indication that something is plugged in.
Looking for thoughts on what could be wrong, and/or debugging steps to take.
My device tree for P75:
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_usbotg>;
vbus-supply = <&vbat>;
status = "okay";