I've read some other posts issuing this problem. But without an solution for exactly this problem. I've installed Ubuntu 14.04 on my Lenovo T440s.
Realtek Semiconductor Co., Ltd. RTS5227 PCI Express Card Reader isn't working on it.
After I pushed a SD Card into the slot, nothing happened.
# lspci
02:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5227 PCI Express Card Reader (rev 01)
    Subsystem: Lenovo Device 220c
    Flags: fast devsel, IRQ 16
    Memory at f0500000 (32-bit, non-prefetchable) [size=4K]
    Capabilities: [40] Power Management version 3
    Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
    Capabilities: [70] Express Endpoint, MSI 00
    Capabilities: [100] Advanced Error Reporting
    Capabilities: [140] Device Serial Number 00-00-00-01-00-4c-e0-00
    Capabilities: [150] Latency Tolerance Reporting
    Capabilities: [158] L1 PM Substates
# lshw
    *-pci:0
         Beschreibung: PCI bridge
         Produkt: Lynx Point-LP PCI Express Root Port 6
         Hersteller: Intel Corporation
         Physische ID: 1c
         Bus-Informationen: pci@0000:00:1c.0
         Version: e4
         Breite: 32 bits
         Takt: 33MHz
         Fähigkeiten: pci pciexpress msi pm normal_decode bus_master cap_list
         Konfiguration: driver=pcieport
         Ressourcen: irq:17 memory:f0500000-f05fffff
       *-generic UNGEFORDERT
            Beschreibung: Unassigned class
            Produkt: RTS5227 PCI Express Card Reader
            Hersteller: Realtek Semiconductor Co., Ltd.
            Physische ID: 0
            Bus-Informationen: pci@0000:02:00.0
            Version: 01
            Breite: 32 bits
            Takt: 33MHz
            Fähigkeiten: pm msi pciexpress cap_list
            Konfiguration: latency=0
            Ressourcen: memory:f0500000-f0500fff
greetz
 
     
     
     
     
     
     
    