From: Len Brown Date: Wed, 13 Nov 2024 02:07:00 +0000 (-0500) Subject: x86/cpu: Add Lunar Lake to list of CPUs with a broken MONITOR implementation X-Git-Tag: v6.13-rc2~4^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c9a4b55431e5220347881e148725bed69c84e037;p=thirdparty%2Fkernel%2Flinux.git 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 Signed-off-by: Dave Hansen Reviewed-by: Rafael J. Wysocki Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown%40intel.com --- diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index d1de300af1737..8ded9f859a3a9 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