Mikrotik RB493g - sdcard not recognized


I am trying to get sdcard reader working on Mikrotik RB493g but without success. It seems to be a solved thing but I tried everything I could already, without success.

As I can see the support for it is present in the device tree (https://github.com/openwrt/openwrt/blob/master/target/linux/ar71xx/files/arch/mips/ath79/mach-rb4xx.c)

-> spi_register_board_info(rb4xx_microsd_info,

Which is also confirmed by device page info (https://openwrt.org/toh/mikrotik/rb493g).

The event of sdcard insertion is not present in dmesg at all.
ls /dev shows no mm* entries.

I'd like to ask if there's something I am doing wrong. Of course, I have tried different sdcards, different sizes.

Thank you in advance.