If I run in Ubuntu 17.04
locate xorg.conf.d | grep d$, here is what I get:
Is it normal to have two folders like these, or is it some side-effect of upgrading the distribution, which I did just before?
Which is, out of the two, the folder that is really used by the system. I have to add a configuration file and I do not know whether to add it in the one or the other.