EDIT: I enabled CONFIG_MSDOS_PARTITION and that caused it to work. It had nothing to do with the device itself but the partition type on the sd card.

Thank you do much rattking for the help!

Original post:

Hi all, I am using a custom configured linux kernel (Gentoo), with very few things enabled. It has done me very well so far and taught me a bunch, but there's one small issue I have been having lately that is annoying. My SD-card reader (a USB device) is not working, but it works perfectly fine on my arch linux laptop without any kernel configurations.

Is it possible to tell which drivers or kernel configurations I need by looking at the laptop that is working?

More context about the issue

On the machine where it is not working, after plugging the device in, I see this in lsblk output:

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda           8:0    1  59.5G  0 disk 
nvme0n1     259:0    0 400G  0 disk 
├─nvme0n1p1 259:1    0     1G  0 part /boot
└─nvme0n1p2 259:2    0 400G  0 part /

The device does show sda but no sda/sda1. This is opposite to the laptop, where I do see a sda1 below the sda device, which I can mount using mount /dev/sda1 /mnt/point

What I tried

I tried enabling the following kernel configurations: MMC MMC_BLOCK MMC_SDHCI MMC_SDHCI_PCI MMC_RICOH_MMC MMC_SDHCI_ACPI

Still, this did not change the result.

I tried looking into the logs, but could not find anything interesting. I am using the sysklogd system logger instead of systemd's journalctl

The reader I bought

I bought this a long time ago from amazon: https://algopix.com/products/B08N4N7Q7J-zhoubin-usb-30-sd-card-reader-for-sdxc-sdhc-sd-mmc-rsmmc-micro-sdxc-micro-sd

Yes I know I cheaped out. But it worked for me until I tried it on this one computer, so I wish to make it work.

Final Question

How can I make this work?