diff options
author | Leah Rowe <leah@libreboot.org> | 2021-12-01 03:00:46 +0000 |
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committer | Leah Rowe <leah@libreboot.org> | 2021-12-01 04:32:02 +0000 |
commit | 9938fa14b1bf54db37c0c18bdfec051cae41448e (patch) | |
tree | c1ab96a280259001743d1f139b257e8e959c9a4b /resources/coreboot/x200_4mb/config/libgfxinit_corebootfb | |
parent | 4b64e34fc2d3ebfe22d350f0b04023fe60e0df3e (diff) |
Fix broken SpeedStep on GM45 laptops such as ThinkPad X200, T400, T500, W500
Coreboot is enabling PECI on these CPUs which, according to Intel erratum, must
only be done after loading microcode updates, otherwise the CPUID feature set
becomes corrupted. That's my understanding, and I think this is why SpeedStep
is broken. To be specific, it could but but operating systems no longer detect
that the feature is supported. In any case, belgin on IRC found the commit in
coreboot, after a bisect, enabling PECI. This commit in Libreboot adds a patch,
reverting coreboot's PECI patch.
Diffstat (limited to 'resources/coreboot/x200_4mb/config/libgfxinit_corebootfb')
0 files changed, 0 insertions, 0 deletions