When you install slack for the first time, it will ask you for a kernel to load... Most people will choose the basic kernel.
The basic kernel will attempt to load as many hardware-specific modules as it sees to be appropriate for the current hardware. Many of these devices you won't even have on your system.
To cut a long story short, you'd be facing less of these "errors" if you were to recompile your kernel to your liking and hardware installed.