Re: VESAFB CUSTOM RESOLUTION

["Antonino A. Daplas" <adaplas@gmail.com>]

On Wed, 2007-07-18 at 13:42 +0300, Al Boldi wrote:
> Geert Uytterhoeven wrote:
> > On Wed, 18 Jul 2007, Sasa Ostrouska wrote:
> Is there any technical reason why vesafb shouldn't support non-BIOS modes?
> 

vesafb can only use modes included by the vendor in the card's BIOS. The
mode table contains standard modes defined by VESA, and perhaps
vendor-defined custom modes. However, the mode ID of custom modes varies
from card to card, so you have to 'probe' the BIOS first for the list of
modes and their associated ID.  X + the 'vesa' driver does that probe,
and so does the lrmi tool vbetest.
 
So, one cannot just set any mode, unless that mode is already defined in
the BIOS mode table. In VBE 3.0, you might be able to choose an
arbitrary vertical refresh rate, but that's the best mode tuning you can
do with the video BIOS. 

Tony