Re: [PATCH] Use MTRRs by default for vesafb on x86-64

Andi Kleen
2003-05-19T10:24:32Z

On Sat, May 17, 2003 at 12:58:39AM +0200, Eric W. Biederman wrote:
> I don't know if this affects the frame buffers per se.
>
> But often BIOS's on systems with large amounts of memory configure
> overlapping mtrrs (where an uncacheable mtrr would override a larger
> cacheable range). To date this has confused the linux mtrr code when
> it tries to modify things, and you cannot properly setup mtrrs. I
> believe this applies to both the fb case as well as X.

Interesting. Perhaps it would be really better to use change_page_attr()
with PAT for this. It would avoid these problems.

-Andi