Re: FB model basic issues (WAS: radeon, apertures & memory mapping)

Ville Syrjälä wrote:
 > I think that making the assumption that all memory is preserved when the

memory layout (virtual resolution and depth) doesn't change is perfectly valid too. That would allow X to do it's Ctrl-Alt-+ and - things without repainting the whole screen.

I'm not sure I agree here, as it's not always true. For instance, the radeon has some restrictions whether it can use tiling or not with a certain mode (interlace/double scan) thus you need to redraw everything anyway (which is exactly why I implemented a driver workaround to repaint everything when that happens - in fact the workaround also gets rid of the offscreen contents, which is not necessary, but was much easier to implement, since I couldn't find an easy way to "invalidate the framebuffer"). What's the big deal with repainting everything? It's not like you would do 100 mode changes per second so it would be performance-critical...

Roland