How does modprobe.d blacklist work, exactly?

## Problem I have conflicting drivers: xpad which comes standard with Arch, and [xone](https://github.com/medusalix/xone) which I installed from [AUR](https://aur.archlinux.org/packages/xone-dkms-git) . Both claim to support my Xbox One wireless controller even though only the xone driver knows what to do with it.

$ modprobe -R usb:v045Ep02F9d0114dcFFdscFFdpFFicFFisc5Dip01in00
xpad
xone_dongle

AFAIU, the culprit is the alias: usb:v045Ep*d*dc*dsc*dp*icFFisc5Dip01in* in the xpad driver which is too inclusive. I want only the xone_dongle loaded for the modalias above. But I don't want to disable the xpad driver completely, because I also use a wired Xbox 360 controller usb:v045Ep028Ed0114dcFFdscFFdpFFicFFisc5Dip01in00 which I still want to be handled by xpad. I don't need them to work at the same time, but at least if I plug one of them after a clean boot, either should work. ## Attempted solution The manual page for modprobe.d states: > the blacklist keyword indicates that all of that particular module's internal aliases are to be ignored. Which sounds like if I blacklist xpad and then define my own alias for it, it should work the way I want: /etc/modprobe.d/gamepad.conf

blacklist xpad
alias usb:v045Ep028Ed0114dcFFdscFFdpFFicFFisc5Dip01in00 xpad

But instead it completely prevents the xpad driver from loading, even though the alias is correct. Also, even though I've blacklisted xpad in the configuration, modprobe -R still finds it for the modalias of the wireless dongle. ## Non-conclusion Can someone please shed some light on how this actually works? Is there a bug in modprobe? Is modprobe.d documentation incomplete? Which aspects of modprobe should be affected by the modprobe.d configuration and which shouldn't?