• USB

USB on FreeBSD

USB is short for Universial Serial BUS. There are currently five variants of USB. The USB stack in FreeBSD -current supports Low-, Full-, High- and Super- speed USB devices in Host- and Device Mode.

• Low Speed USB
• Full Speed USB
• High Speed USB
• Super Speed USB
• Wireless USB (not supported yet)

Debugging USB

If you want very verbose messages, you can set the following variables in loader.conf

hw.usb.ehci.iaadbug=1
hw.usb.ehci.debug=1
hw.usb.xhci.debug=1

usbconfig gives you information on your devices. If you run it with the list argument, or no argument it prints a list of your devices.

$ sudo usbconfig
ugen0.1: <0x8086 XHCI root HUB> at usbus0, cfg=0 md=HOST spd=SUPER (5.0Gbps) pwr=SAVE (0mA)
ugen1.1: <Intel EHCI root HUB> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA)
ugen1.2: <vendor 0x8087 product 0x8000> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA)
ugen0.2: <Microsoft Wired Keyboard 600> at usbus0, cfg=0 md=HOST spd=LOW (1.5Mbps) pwr=ON (100mA)
ugen0.3: <VXIS Inc FHD Webcamera> at usbus0, cfg=255 md=HOST spd=SUPER (5.0Gbps) pwr=ON (100mA)

You can get more detailed information on your devices with the dump_all_desc command. Note the addressing after the -d arg, this is the common format for most commands, you can use either ugen0.3, or just 0.3.

$ sudo usbconfig -d 0.3 dump_all_desc
ugen0.3: <VXIS Inc FHD Webcamera> at usbus0, cfg=255 md=HOST spd=SUPER (5.0Gbps) pwr=ON (100mA)

  bLength = 0x0012
  bDescriptorType = 0x0001
  bcdUSB = 0x0310
  bDeviceClass = 0x00ef  <Miscellaneous device> 
  bDeviceSubClass = 0x0002
  bDeviceProtocol = 0x0001
  bMaxPacketSize0 = 0x0009
  idVendor = 0x1bcf
  idProduct = 0x2c99
  bcdDevice = 0x0200
  iManufacturer = 0x0001  <VXIS Inc>
  iProduct = 0x0002  <FHD Webcamera>
  iSerialNumber = 0x0000  <no string>
  bNumConfigurations = 0x0001

The key take away points here (other than obvious things like the power setting) are:

• The cfg=255 from usbconfig indicates that the device was not initialized correctly.
• idVendor and idProduct (not iProduct) are the vendor and product ids, used in a number of places like setting quirks

HPSUSB FAQ

• Q: I see the following error and USB stops working "Page offset was not preserved!"
• A: Update your sources, this issue is fixed.
• Q: I can't boot my Freesbie using USB2.
• A: Update your sources, this issue is fixed.
• Q: Screen updates in X11 are slow/broken/laggy
• A: Ensure your kernel/world is up to date, old libs removed and the libpciaccess port is rebuilt.
• Q: My mass storage device is not working, what can I do?
• A: If your mass storage device needs a quirk, because it does not conform to the SCSI specification you can add it in the following way:

  # 1) Unload "umass" if it is loaded.
  # 2) Plug your device.
  # 3) You might have to add a new entry for your device in /sys/dev/usb/usbdevs .
  # 4) To get the VID+PID for your device you run "usbconfig -u X -a Y dump_device_desc"
  # where X and Y are the numbers reported by ugen.
  # For example:
  usbconfig -u 4 -a 7 dump_device_desc
  
  # 5) Try adding an entry in the quirktable in /sys/dev/usb/quirk/usb_quirk.c . 
  # Look at the other quirks for examples.