Secuence of actions shown:

- installed usb_rndis driver.
- connected USB cable.
- enabled USB-tethering on the phone.
- disabled tethering on the phone.
- KDL / reboot.
- thankfully, this time the needed info was still found in /var/log/syslog

KERN: usb hub 36: port 0: new device connected
KERN: usb_audio:33.09.367:init_driver::ver.0.0.5
KERN: usb hub 36: KERN: port 0: new device connected
KERN: usb error hub 36: new device on a port that is already in use
KERN: usb_audio:33.25.727:init_driver::ver.0.0.5
KERN: usb_rndis: init_hardware()
KERN: usb_rndis: init_driver()
KERN: usb_rndis: rndis device 0 added
KERN: usb_rndis: publish_devices()
KERN: usb_rndis: publishing net/usb_rndis/0
KERN: usb_rndis: find_device(net/usb_rndis/0)
KERN: usb_rndis: open(net/usb_rndis/0, 2, 0xffffffff8a2fd530)
KERN: usb_rndis: Send init command results in No error
KERN: usb_rndis: Received notification 1 0
KERN: usb_rndis: Received notification after init command
KERN: usb_rndis: Read init command results in No error
KERN: usb_rndis: Type      80000002
KERN: usb_rndis: Length    34
KERN: usb_rndis: Req ID    0
KERN: usb_rndis: Status    0
KERN: usb_rndis: Vers Maj  1
KERN: usb_rndis: Vers Min  0
KERN: usb_rndis: DevFlags  1
KERN: usb_rndis: Medium    0
KERN: usb_rndis: Max Pkts  1
KERN: usb_rndis: Max Bytes 62c
KERN: usb_rndis: Alignment 0
KERN: usb_rndis: Reserved  KERN: usb_rndis: 0 usb_rndis: 0 KERN: usb_rndis: 
KERN: usb_rndis: Received notification 1 0
KERN: usb_rndis: mac address: 62:8f:66:87:ff:ff
KERN: usb_rndis: Received notification 1 0
KERN: usb error ehci 4: qtd (0x7f48300) error: 0x801c0d50
KERN: usb_rndis: failed to read fragment siez
KERN: usb error ehci 4: qtd (0x7f48080) error: 0x80088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to read media state
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: KERN: qtd (0x7f48580) error: 0x801c0049
KERN: usb error ehci 4: qtd (0x7f48a00) error: 0x801c0049
KERN: usb_rndis: failed to read link speed
KERN: usb error ehci 4: qtd (0x7f48b80) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: Failed to start traffic (set oid: Operation timed out)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
KERN: usb_rndis: Initialization result: Operation timed out
DAEMON 'DHCP': /dev/net/usb_rndis/0: Timeout shift: 500 msecs (try 1)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
DAEMON 'DHCP': /dev/net/usb_rndis/0: Timeout shift: 1000 msecs (try 2)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
DAEMON 'DHCP': /dev/net/usb_rndis/0: Timeout shift: 2000 msecs (try 3)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f48e00) error: 0x80200049
KERN: usb error ehci 4: qtd (0x7f49180) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
DAEMON 'DHCP': /dev/net/usb_rndis/0: Timeout shift: 4000 msecs (try 4)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f49500) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: KERN: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f49880) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
DAEMON 'DHCP': /dev/net/usb_rndis/0: Timeout shift: 8000 msecs (try 5)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f49c00) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f49f80) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4a300) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4a680) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
DAEMON 'DHCP': /dev/net/usb_rndis/0: Timeout shift: 60000 msecs (try 6)
DAEMON 'DHCP': /dev/net/usb_rndis/0: Send DHCP_DISCOVER to 255.255.255.255:67
KERN: usb error control pipe 128: KERN: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4aa00) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4ad80) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4b100) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4b480) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4b800) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4bb80) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4bf00) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4c280) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4c600) error: 0x00088148
KERN: usb_rndis: device status error 0x8000a014
KERN: usb hub 36: KERN: port 0: device removed
KERN: usb error control pipe 128: timeout waiting for queued request to complete
KERN: usb_rndis: failed to clear halt state in notify hook
KERN: usb error ehci 4: qtd (0x7f4c800) error: 0x80008148
KERN: write access attempted on write-protected area 0x3739 at 0xffffffff8cd20000
KERN: vm_page_fault: vm_soft_fault returned error 'Permission denied' on fault at 0xffffffff8cd20008, ip 0xffffffff8766802a, write 1, user 0, exec 0, thread 0x12