From 81ce24baf515fa78b8748caf4d8698097f68ca0d Mon Sep 17 00:00:00 2001 From: Len Brown Date: Tue, 12 Nov 2024 21:07:00 -0500 Subject: [PATCH] [NOT FOR UPSTREAM] x86/cpu: Add INTEL_LUNARLAKE_M to X86_BUG_MONITOR Under some conditions, MONITOR wakeups on Lunar Lake processors can be lost, resulting in significant user-visible delays. Add LunarLake to X86_BUG_MONITOR so that wake_up_idle_cpu() always sends an IPI, avoiding this potential delay. Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219364 Cc: stable@vger.kernel.org # 6.11 Signed-off-by: Len Brown Link: https://lore.kernel.org/lkml/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown@intel.com/ Signed-off-by: Kai Vehmanen --- 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 e7656cbef68d54..4b5f3d0521517a 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -586,7 +586,9 @@ 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