One Kernel For All

> Now that there are mobile devices running Linux based non-Android distros and people using them that probably want frequent suspends to reduce power usage there but the corresponding distros won't be enabling CONFIG_PM_USERSPACE_AUTOSLEEP in their main builds that are used on desktops and servers, does that mean distros need a second Linux kernel build just for mobile devices that want the behaviour?

I don't see an issue in requiring distros that ship mobile GUI frontends to also ship their own kernel. You probably already don't want to ship your server's kernel (see preemption settings) and you're going to be shipping completely different images for desktop vs. ARM handset already anyway. Asking a distro to have a second kernel package for an entirely different class of device really isn't that big of a deal, especially when said kernel likely needs certain things for powersaving and Android compatibility tuned for it.

For what it's worth, my experience in the ARM ecosystem is that we'll never get to have one kernel that fits all use cases there simply due to all the erratas and different device requirements.