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On Sun, Aug 15, 2010 at 6:27 PM, Walter Dnes <waltdnes@××××××××.org> wrote: |
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> I'm running 64-bit Gentoo on an Intel 4-core i3 with an Intel integrated |
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> graphics controller. An excerpt from dmesg follows, with the video- |
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> related stuff. Note the two lines that I've split off. They mention |
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> the mtrr type mismatch and the allocation failure. Is this a problem |
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> and if so, what do I do about it? |
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|
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... |
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|
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> [ 0.608643] mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining |
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> [ 0.608725] [drm] MTRR allocation failed. Graphics performance may suffer. |
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|
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I had a similar message, it was there because of the fact that i |
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specified the wrong (or failed to specify?) mtrr method in my kernel |
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boot parameters for the framebuffer. I'm using uvesafb and in kernel |
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documentation (/usr/src/linux/Documentation/fb/uvesafb.txt) it |
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explains the values and even gives an example of this error and what |
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to do about it: |
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|
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<cut> |
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mtrr:n Setup memory type range registers for the framebuffer |
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where n: |
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0 - disabled (equivalent to nomtrr) (default) |
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1 - uncachable |
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2 - write-back |
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3 - write-combining |
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4 - write-through |
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|
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If you see the following in dmesg, choose the type that matches |
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the old one. In this example, use "mtrr:2". |
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... |
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mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining |
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... |
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</cut> |
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|
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After I changed my mtrr setting in grub's config & rebooted, the error |
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message went away. |
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|
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HTH :) |