Alan Cox <alan@linux.intel.com> Wrote 2016/09/07 05:16:49:

> Alan Cox <alan@linux.intel.com>
> 2016/09/07 05:16
> Re: [RFC] drm/gma500: add virtual mapping support for fbdev.
>
> On Tue, 2016-09-06 at 19:28 +0800, jiang.biao2@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
>

In addition to plymouth, one of our own app is using the fbdev
directly too, so encounter the problem. Maybe it should also use DRM.

Thanks for you reply.