Setup SD Card Reader on Debian 10

Question

I want to use the sd card reader on my ASUS UX501VW-FY144T. Via hw-probe (link) one can see that the sd card is a Alcor Micro AU6621, which isn't configured correct.

So I updated to the kernel version 5.10.:

 ~ cat /proc/version                                                                           
Linux version 5.10.0-0.bpo.3-amd64 ([email protected]) (gcc-8 (Debian 8.3.0-6) 8.3.0, GNU ld (GNU Binutils for Debian) 2.31.1) #1 SMP Debian 5.10.13-1~bpo10+1 (2021-02-11)

Now there should be support for this card reader according to github.

But on insertion nothing happens. dmesg prints nothing and lsusb, lsblk, lscpi don't list the sd card reader.

UPDATE:

Output of lspci -nn -d 1aea:::

02:00.0 Unassigned class [ff00]: Alcor Micro Device [1aea:6621]

Output of grep -e MISC_ALCOR_PCI -e MMC_ALCOR -e MFD_CORE -e MMC /boot/config-5.10.*:

CONFIG_PCI_MMCONFIG=y
CONFIG_MMCONF_FAM10H=y
# CONFIG_MISC_ALCOR_PCI is not set
CONFIG_MFD_CORE=y
# MMC/SDIO DVB adapters
CONFIG_MMC=m
CONFIG_MMC_BLOCK=m
CONFIG_MMC_BLOCK_MINORS=256
# CONFIG_MMC_TEST is not set
# MMC/SD/SDIO Host Controller Drivers
# CONFIG_MMC_DEBUG is not set
CONFIG_MMC_SDHCI=m
CONFIG_MMC_SDHCI_IO_ACCESSORS=y
CONFIG_MMC_SDHCI_PCI=m
CONFIG_MMC_RICOH_MMC=y
CONFIG_MMC_SDHCI_ACPI=m
# CONFIG_MMC_SDHCI_PLTFM is not set
CONFIG_MMC_WBSD=m
CONFIG_MMC_TIFM_SD=m
# CONFIG_MMC_SPI is not set
CONFIG_MMC_SDRICOH_CS=m
CONFIG_MMC_CB710=m
CONFIG_MMC_VIA_SDMMC=m
CONFIG_MMC_VUB300=m
CONFIG_MMC_USHC=m
# CONFIG_MMC_USDHI6ROL0 is not set
CONFIG_MMC_REALTEK_PCI=m
CONFIG_MMC_REALTEK_USB=m
CONFIG_MMC_CQHCI=m
# CONFIG_MMC_HSQ is not set
CONFIG_MMC_TOSHIBA_PCI=m
# CONFIG_MMC_MTK is not set
CONFIG_MMC35240=m
# CONFIG_PHY_INTEL_LGM_EMMC is not set

Any ideas? Thanks in advance! Luke

Answer 1

02:00.0 Unassigned class [ff00]: Alcor Micro Device [1aea:6621]

According to the PCI vendor and product IDs, this is the card reader. The lspci command just does not have a product name for it yet. You could get the PCI device ID database updated by running sudo /usr/sbin/update-pciids, but it will only allow the device to be identified by product name in the lspci listing: it will have no effect for actual hardware support.

# CONFIG_MISC_ALCOR_PCI is not set

This indicates the driver for the card reader's bus interface is not enabled in the kernel configuration. If it was enabled as a module, you'd see CONFIG_MISC_ALCOR_PCI=m instead. And since this is a dependency for the actual card reader driver (CONFIG_MMC_ALCOR), the kernel configurator is not even allowing to select the card reader driver unless its bus interface is enabled first, and so the CONFIG_MMC_ALCOR line does not appear at all.

The other dependencies seem to be already available as modules.

You might have to compile your own, very slightly customized kernel package, using the backport kernel's configuration (at /boot/config-5.10.*) as a starting point, and just change it to set the two above-mentioned options to be built as modules.

Note that if your system uses UEFI, you might need to disable Secure Boot in order to be able to boot custom kernels without signing them yourself. Once your custom kernel boots successfully with Secure Boot disabled, you can then work towards satisfying the Secure Boot requirements and re-enabling Secure Boot, if you wish.

(If you are not already familiar with it, the kernel build procedure is enough of a challenge without adding Secure Boot to the mix. One step at a time.)