[RFC] drm/gma500: add virtual mapping support for fbdev.

[Alan Cox]

On Tue, 2016-09-06 at 19:28 +0800, jiang.biao2 at zte.com.cn wrote:
> Hi, 
> 
> I found current gma500 fbdev driver does not support the virtual 
> mapping for the fb pages, instead it only uses stolen pages and 
> supports high resolution console by reducing the color depth. It 
> works well with fbcon for high resolution envirnment. 

The text mode console code can't support a non-linear mapping and
trying to grab one used most or all of the vmalloc address space on a
32bit box (and most of those systems are only able to run 32bit).

For the sake of a bootscreen loader (which could use DRM directly
instead if it needed high resolution) it didn't seem worht it.

Either way it's not IMHO a good idea for 32bit, 64bit maybe.

Alan