Strange video mode output with VESA

[Jung-uk Kim]

On Wednesday 02 June 2010 04:25 pm, David DEMELIER wrote:
> Hi there,
>
> I was so happy to see that VESA is available for amd64, but
> unfortunately it does not work really well for me. Take a look at
> this picture :
>
> http://img717.imageshack.us/img717/7311/dsc00399h.jpg
>
> My laptop is a 15,6" so the best resolution is 1366x768, I tried
> this
>
> : vidcontrol MODE_496. As you can see on the picture all the lines
> : are
>
> completely everywhere, if I mouse the cursor they move away (I'm
> not drunk!).
>
> I have SC_PIXEL_MODE in my kernel config.
>
> The console terminal is okay until I don't excess 1280x960x32 video
> mode.
>
> Do you have any idea to fix this ?

It is kinda known problem.  If the mode has larger bytes per scan line 
than the minimum, few characters per line are lost when the screen is 
scrolled up or down, i.e., framebuffer copies of whole screen.  When 
you move the mouse onto the line, entire line is redrawn and 
restored.  That's what you are seeing.  Ed might have a better idea 
how to fix it (CC'ed).

Jung-uk Kim