Disable external hubs

configname: CONFIG_USB_OTG_BLACKLIST_HUB

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>Disable external hubs
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
If you say Y here, then Linux will refuse to enumerate
external hubs. OTG hosts are allowed to reduce hardware
and software costs by not supporting external hubs.

depends
CONFIG_USB_OTG

is selected by
CONFIG_USB_MUSB_JZ4740