Xorg causes panics with "multiple" drivers (Was: panic: resource_list_alloc: resource entry is busy)

[dt71 at gmx.com]

John Baldwin wrote on 09/12/2014 23:06:
> X loaded i915kms automatically and
> i915 and i915kms do not get along.  i915 had already allocated the IRQ
> when i915kms tried to alloc the same IRQ causing the issue.

Who is to blame? The user who tried to manually load an unsupported combination of modules, or the system, which should have handled things gracefully (whether by automatically unloading the first driver, or producing a soft-error upon loading the 2nd driver)?

On a side-note, I also had a "resource_list_alloc: resource entry is busy" panic right after switching from the 10.0-supported Xorg to the "new" Xorg; I exited Xorg, enabled "FreeBSD_new_Xorg", ran "pkg upgrade", then ran "startx", and got the panic. Surely this wasn't my fault!