Re: [PATCH] VESA framebuffer w/ MTRR locks 2.4.0 on init

Alan Cox
2001-01-05T16:52:35Z

> Dough! I normally use ywrap scrolling, the memory thing means that I get a big
> "black hole" every time I get down to that last 64k of memory, and before the
> pointer to the console's display resets back to "top" of the memory region. The
> only way I've found to get around this is to force the size of the video memory.
> Does this mean that there's a problem with the display adapter that it wraps reads
> of video memory at the 2048k boundary? Is the 64k used by the Crystal 4232 and/or
> OPL3? If so, why doesn't listening to sounds screw with my fbcon?

Its used on the chip for the onboard audio. See drivers/sound/nm256*. If you
have other sound chips then it is probably not needed.

yywrap is a hack rather than generally safe feature and its not guaranteed that
your videoram wraps neatly. Really the driver should have spotted the hole I
guess.

Alan