Re: vesafb-fix-mtrr-bugs.patch added to -mm tree

From: Dave Jones
Date: Fri Jul 29 2005 - 14:03:41 EST

On Fri, Jul 29, 2005 at 11:24:37AM -0700, Andrew Morton wrote:

> From: "Antonino A. Daplas" <adaplas@xxxxxxxxx>
> >> vesafb: mode is 800x600x16, linelength=1600, pages=16
> >> vesafb: scrolling: redraw
> >> vesafb: Truecolor: size=0:5:6:5, shift=0:11:5:0
> >> mtrr: type mismatch for fc000000,1000000 old: write-back new: write-
> >> combining
> Range is already set to write-back, vesafb attempts to add a write-combining
> mtrr (default for vesafb).
> >> mtrr: size and base must be multiples of 4 kiB
> This is a bug, vesafb attempts to add a size < PAGE_SIZE triggering
> the messages below.

I fixed this a few weeks back. It's this line which your patch removes..

- while (temp_size > PAGE_SIZE &&

> To eliminate the warning messages, you can add the option mtrr:2 to add a
> write-back mtrr for vesafb. Or just use nomtrr option.

If we need users to pass extra command line args to make warnings go
away, we may as well not bother. Because 99% of users will be completely
unaware that option even exists. They'll still see the same message,
and still report the same bugs.

The pains of MTRR strike again. This stuff is just screaming for
a usable PAT implementation. Andi, you were working on that, any news ?
Or should I resurrect Terrence's patch again ?


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