laktak:

I had to install kmod-usb3 to get usb working. I think this should be included in the default distribution.

Supply the following if possible:

• Device problem occurs on
  Netgear R6220

• Software versions of LEDE release, packages, etc.
  DISTRIB_ID='LEDE'
  DISTRIB_RELEASE='SNAPSHOT'
  DISTRIB_REVISION='r3925-64175ff'
  DISTRIB_CODENAME='reboot'
  DISTRIB_TARGET='ramips/mt7621'
  DISTRIB_ARCH='mipsel_24kc'
  DISTRIB_DESCRIPTION='LEDE Reboot SNAPSHOT r3925-64175ff'
  DISTRIB_TAINTS='no-all'

• Steps to reproduce
  dmesg # notice no usb support
  opkg update && opkg install kmod-usb3
  dmesg # now shows usb support

e.g.
[ 586.090000] hub 1-0:1.0: USB hub found
[ 586.100000] hub 1-0:1.0: 2 ports detected
[ 586.110000] xhci-mtk 1e1c0000.xhci: xHCI Host Controller
[ 586.120000] xhci-mtk 1e1c0000.xhci: new USB bus registered, assigned bus number 2
[ 586.140000] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[ 586.160000] hub 2-0:1.0: USB hub found
[ 586.160000] hub 2-0:1.0: 1 port detected
[ 586.560000] usb 1-2: new high-speed USB device number 2 using xhci-mtk
...