I have some info that I think could help narrow this down and feel like I now
at least have a trail to pursue. The SD card reader works in Fedora 30 Rawhide
but not in the 29 iso. This means that between kernel 4.18 and 5.0 the
maintainers in Fedora made a change to their config that made this start
working. I could probably narrow this down even further by installing Fedora
release 29 and testing each of the kernels that hit the repos to see if it was
fixed before 5.0rc4. I am going to take a diff of the Fedora config files for
those kernels to see if anyhing sticks out. Since it is from the same distro, I
figure it should be pretty digestible. I am going to try the experimental
kernel in Debian and see if that fixes the issue as well.
Summary of what we know so far:
Kernel 4.19 in Debian Sid not working with reader.
Kernel 4.18 in Ubuntu 18.10 iso works with reader.
Kernels 4.19 and 4.20 work with reader in arch
Kernel 4.18 on Fedora 29 iso not working
but 5.0 rc4 in rawhide is.