On Wed, Sep 21, 2022 at 07:15:07AM -0700, Dave Hansen wrote: > In the end, the delay is because of buggy, circa 2006 chipsets? So, we > use a CPU vendor specific check to approximate that the chipset is > recent and not affected by the bug? If so, is there no better way to > check for a newer chipset than this? So I did some git archeology but that particular addition is in some conglomerate, glued-together patch from 2007 which added the cpuidle tree: commit 4f86d3a8e297205780cca027e974fd5f81064780 Author: Len Brown <len.brown@xxxxxxxxx> Date: Wed Oct 3 18:58:00 2007 -0400 cpuidle: consolidate 2.6.22 cpuidle branch into one patch so the most precise check here should be to limit that dummy read to that Intel chipset which needed it. Damned if I knew how to figure out which... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette