[coreboot] OT: Submitted MTRR patches for Linux kernel

[Paul Menzel]

Dear coreboot folks,


just a note to inform you, that Andy Lutomirski sent some MTRR patches
to the Linux kernel lists [1] with the following cover letter.

        [PATCH 0/7] Clean up write-combining MTRR addition

        A fair number of drivers (mostly graphics) add write-combining MTRRs.
        Most ignore errors and most add the MTRR even on PAT systems which don't
        need to use MTRRs.

        This series adds new functions mtrr_{add,del}_wc_if_needed and
        drm_mtrr_{add,del}_wc that report errors and do nothing if PAT is
        enabled.

        I've only tested the radeon driver, since I don't have test hardware
        easily available for the other drivers.

        Benefits include:
         - Simpler code
         - No more complaints about MTRR conflict warnings on PAT systems
         - Eventual unexporting of the MTRR API?

        This series eliminates about half of the mtrr_add calls in drivers/.

        The series is also at:
        https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=mtrr_cleanup

        Andy Lutomirski (7):
          x86: Add mtrr_{add,del}_wc_if_needed
          drm (ast,cirrus,mgag200,nouveau,savage,vmwgfx): Rework drm_mtrr_{add,del}
          drm: Update drm_addmap and drm_mmap to use PAT WC instead of MTRRs
          drm: Use drm_mtrr_add_wc for the AGP aperture
          i915: Use drm_mtrr_{add,del}_wc
          radeon: Switch to drm_mtrr_add_wc and add a missing drm_mtrr_del_wc
          uvesafb: Clean up MTRR code

I have not looked at them, but maybe some of the ideas can be used for
coreboot too.


Thanks,

Paul


[1] http://www.spinics.net/lists/dri-devel/msg38048.html
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