I have the same problem. I just bought USB3.0 CF-reader and it doesn't working under Ubuntu 12.04 (Linux 3.2.0-25-generic). This reader works great in Win7.
I didnt checked before, but I also dont have xhci-hcd module
USB controler in x220:
#find / -name *xhci?hcd*
Card reader MODECOM CR-Level3:
# lspci | grep USB
NEC Corporation uPD720200 USB 3.0 Host Controller (rev 04)
Dmesg after connect
Bus 004 Device 005: ID 05e3:0732 Genesys Logic, Inc.
[ 2253.615694] usb 4-1: new SuperSpeed USB device number 6 using xhci_hcd
[ 2253.638880] scsi10 : usb-storage 4-1:1.0
[ 2254.639422] scsi 10:0:0:0: Direct-Access Generic STORAGE DEVICE 0542 PQ: 0 ANSI: 0
[ 2254.641497] sd 10:0:0:0: Attached scsi generic sg1 type 0
[ 2254.642784] sd 10:0:0:0: [sdb] Attached SCSI removable disk
PROBLEM SOLVED after upgrading kernel to 3.2.0-26-generic