Re: SD Card Reader.
If a driver claims the device then you'll get a message in /var/log and likely an entry like
/dev/mmcblk01 in /dev/
You can also monitor udev events as you plug it in.
If nothing claims the device then Linux can't write to it.
In any case
MAYBE these devices have defective electronics and are unusable.
MAYBE these devices have no partiton table and you just need to run gparted or fdisk over them.
None are more hopelessly enslaved than those who falsely believe they are free.
Johann Wolfgang von Goethe