We have made a custom board based on the mangoh red device and are having some issues with the USB hub not enumerating correctly after a reboot. Sometimes, after a reboot, we see only the root hub and not the microchip hub.
We have chosen to go with another power supply setup and another oscillator for the USB hub than on the mangoh so therefore we might have some timing problems between the startup of the oscillator and the usb hub.
On the board we have the possibillity of controlling the reset of the USB hub via a GPIO instead of reset out, however, that causes some problems in the boot process in that the driver for the hsic root hub is loaded before the USB hub is available and therefore nothing is loaded when the processor boots.
I am therefore in the process of trying to figure out which driver adds support for the HSIC root hub and compile that as a module in the kernel to try to figure out if we can overcome our issues by resetting the usb hub via a gpio and then reloading the driver.
Does anyone know which driver I need to compile as a module to be able to control when it is loaded?