From c7f6fa44115d401e89db730f357629d39f8e4ba6 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Tue, 28 Jul 2009 23:52:54 +0200 Subject: [PATCH] x86, mce: don't log boot MCEs on Pentium M (model == 13) CPUs On my legacy Pentium M laptop (Acer Extensa 2900) I get bogus MCE on a cold boot with CONFIG_X86_NEW_MCE enabled, i.e. (after decoding it with mcelog): MCE 0 HARDWARE ERROR. This is *NOT* a software problem! Please contact your hardware vendor CPU 0 BANK 1 MCG status: MCi status: Error overflow Uncorrected error Error enabled Processor context corrupt MCA: Data CACHE Level-1 UNKNOWN Error STATUS f200000000000195 MCGSTATUS 0 [ The other STATUS values observed: f2000000000001b5 (... UNKNOWN error) and f200000000000115 (... READ Error). To verify that this is not a CONFIG_X86_NEW_MCE bug I also modified the CONFIG_X86_OLD_MCE code (which doesn't log any MCEs) to dump content of STATUS MSR before it is cleared during initialization. ] Since the bogus MCE results in a kernel taint (which in turn disables lockdep support) don't log boot MCEs on Pentium M (model == 13) CPUs by default ("mce=bootlog" boot parameter can be be used to get the old behavior). Signed-off-by: Bartlomiej Zolnierkiewicz Reviewed-by: Andi Kleen Signed-off-by: H. Peter Anvin Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mcheck/mce.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 1cfb623ce11..a0c2910d96a 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1273,6 +1273,10 @@ static void mce_cpu_quirks(struct cpuinfo_x86 *c) if ((c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xe)) && monarch_timeout < 0) monarch_timeout = USEC_PER_SEC; + + /* There are also broken BIOSes on some Pentium M systems. */ + if (c->x86 == 6 && c->x86_model == 13 && mce_bootlog < 0) + mce_bootlog = 0; } if (monarch_timeout < 0) monarch_timeout = 0; -- 2.20.1