Re: [gentoo-user] dmesg warning about mtrr: type mismatch and allocation failed

["Walter Dnes" <waltdnes@waltdnes.org>]

On Mon, Aug 16, 2010 at 05:55:04PM -0500, Paul Hartman wrote
> 
> I had a similar message, it was there because of the fact that i
> specified the wrong (or failed to specify?) mtrr method in my kernel
> boot parameters for the framebuffer. I'm using uvesafb and in kernel
> documentation (/usr/src/linux/Documentation/fb/uvesafb.txt) it
> explains the values and even gives an example of this error and what
> to do about it:

  I'm using the Intel driver, which doesn't have those settings.  And
no, I do not want to drop down to a generic VESA driver with no hardware
acceleration.  Some more Google searching has turned up a lead.
Apparently, it's possible to manually set the mtrr's, using cat and echo
with /proc/mtrr

  According to "lspci -v", my integrated graphics chip has

        Memory at fb800000 (64-bit, non-prefetchable) [size=4M]
        Memory at d0000000 (64-bit, prefetchable) [size=256M]

  My mtrr setup, however, shows up like so...

waltdnes@i3 ~ $ cat /proc/mtrr
reg00: base=0x000000000 (    0MB), size= 8192MB, count=1: write-back
reg01: base=0x200000000 ( 8192MB), size= 1024MB, count=1: write-back
reg02: base=0x0c0000000 ( 3072MB), size= 1024MB, count=1: uncachable
reg03: base=0x0b4000000 ( 2880MB), size=   64MB, count=1: uncachable
reg04: base=0x0b8000000 ( 2944MB), size=  128MB, count=1: uncachable
reg05: base=0x1fc000000 ( 8128MB), size=   64MB, count=1: uncachable

  I'll read up more on how to set it up manually.  One thing that has my
curiousity right now... how come there's a gig of ram in write-back mode
*STARTING* at 8 gigs, and ending at 9 gigs minus 1 byte, when I only
have 8 gigs of ram in total?

-- 
Walter Dnes <waltdnes@waltdnes.org>