The following commit has been merged into the x86/urgent branch of tip: Commit-ID: c9a4b55431e5220347881e148725bed69c84e037 Gitweb: https://git.kernel.org/tip/c9a4b55431e5220347881e148725bed69c84e037 Author: Len Brown <len.brown@xxxxxxxxx> AuthorDate: Tue, 12 Nov 2024 21:07:00 -05:00 Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> CommitterDate: Wed, 04 Dec 2024 12:30:14 -08:00 x86/cpu: Add Lunar Lake to list of CPUs with a broken MONITOR implementation Under some conditions, MONITOR wakeups on Lunar Lake processors can be lost, resulting in significant user-visible delays. Add Lunar Lake to X86_BUG_MONITOR so that wake_up_idle_cpu() always sends an IPI, avoiding this potential delay. Reported originally here: https://bugzilla.kernel.org/show_bug.cgi?id=219364 [ dhansen: tweak subject ] Signed-off-by: Len Brown <len.brown@xxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Cc:stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/all/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown%40intel.com --- arch/x86/kernel/cpu/intel.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index d1de300..8ded9f8 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -555,7 +555,9 @@ static void init_intel(struct cpuinfo_x86 *c) c->x86_vfm == INTEL_WESTMERE_EX)) set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR); - if (boot_cpu_has(X86_FEATURE_MWAIT) && c->x86_vfm == INTEL_ATOM_GOLDMONT) + if (boot_cpu_has(X86_FEATURE_MWAIT) && + (c->x86_vfm == INTEL_ATOM_GOLDMONT || + c->x86_vfm == INTEL_LUNARLAKE_M)) set_cpu_bug(c, X86_BUG_MONITOR); #ifdef CONFIG_X86_64
