I have met on board USB hub enum failed. and list in [On board USB Hub can not be detected]
I found that, When the enum failed, the amplitude of USB_DP is a little lower than the amplitude of enum successful one(Using the same nano module and the same carrier board).
Why did this difference happened? Should I adjust the HS_CURR_LEVEL or HS_SLEW? How can I update the offest of HS_CURR_LEVEL in kernel?