On a Lenovo W541 the O2 Micro SD Card Reader is not loaded.
- model: O2 Micro MMC/SD Card reader 8520
- lspci: "SD Host controller: O2 Micro, Inc. SD/MMC Card Reader Controller (rev 01)"
- kernel: 4.9.25-24.lts
- Setting "CONFIG_PCI_MMCONFIG" should resolve