I have a Thinkpad keyboard with an integrated mouse like http://support.lenovo.com/us/en/documents/migr-73183. # usbconfig -d ugen0.2 dump_device_desc ugen0.2: <ThinkPad USB Keyboard with TrackPoint Lite-On Technology Corp.> at usbus0, cfg=0 md=HOST spd=LOW (1.5Mbps) pwr=ON (100mA) bLength = 0x0012 bDescriptorType = 0x0001 bcdUSB = 0x0110 bDeviceClass = 0x0000 bDeviceSubClass = 0x0000 bDeviceProtocol = 0x0000 bMaxPacketSize0 = 0x0008 idVendor = 0x17ef idProduct = 0x6009 bcdDevice = 0x0127 iManufacturer = 0x0001 <Lite-On Technology Corp.> iProduct = 0x0002 <ThinkPad USB Keyboard with TrackPoint> iSerialNumber = 0x0000 <no string> bNumConfigurations = 0x0001 With a GENERIC kernel, the mouse doesn't work until this quirk: # usbconfig add_dev_quirk_vplh 0x17ef 0x6009 0x0000 0xffff UQ_HID_IGNORE The quirk wasn't necessary in the past when I was versions older than 10. Thanks to frogs in #freebsd on freenode for helping me debug this.
I had only done # kldload ums after booting for the first time. After putting ums_load="YES" in /boot/loader.conf, ums wins the race and the mouse works in Xorg without the quirk.