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
rts_pstor
module manually. It wasn't available by default on my Debian system. – Fred Schoen Oct 29 '17 at 15:08