[RFC 4/4] drm: Add NVIDIA Tegra support

[Alan Cox]

> Maybe your question is answered by my reply to Alan's comment. The mapping
> is actually done to get a linear view for the display controller which
> doesn't support SG transfers. The kernel and user-space already have virtual
> linear buffers.

The framebuffer currently needs a physically contiguous map for the
console devices. Well you could vmap them but that is pretty hideous on a
32bit platform with 32bit 1080p display plugged into it!

Alan