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authorJacob Pan <jacob.jun.pan@linux.intel.com>2011-11-10 17:43:05 +0400
committerIngo Molnar <mingo@elte.hu>2011-11-10 19:21:01 +0400
commit064a59b6dd1f341cc478c212bb436e3da9cb8d04 (patch)
tree44a5075e6b913493391911a57ebbe3cc6a25c26e /arch/x86/platform
parent0a9153261d54c432bc0bdc88607f24c835ac729c (diff)
downloadlinux-064a59b6dd1f341cc478c212bb436e3da9cb8d04.tar.xz
x86/mrst: Avoid reporting wrong nmi status
Moorestown/Medfield platform does not have port 0x61 to report NMI status, nor does it have external NMI sources. The only NMI sources are from lapic, as results of perf counter overflow or IPI, e.g. NMI watchdog or spin lock debug. Reading port 0x61 on Moorestown will return 0xff which misled NMI handlers to false critical errors such memory parity error. The subsequent ioport access for NMI handling can also cause undefined behavior on Moorestown. This patch allows kernel process NMI due to watchdog or backrace dump without unnecessary hangs. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> [hand applied] Signed-off-by: Alan Cox <alan@linux.intel.com>
Diffstat (limited to 'arch/x86/platform')
-rw-r--r--arch/x86/platform/mrst/mrst.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/platform/mrst/mrst.c b/arch/x86/platform/mrst/mrst.c
index b7f14e5b2c66..9b9ee292c107 100644
--- a/arch/x86/platform/mrst/mrst.c
+++ b/arch/x86/platform/mrst/mrst.c
@@ -277,6 +277,17 @@ static void mrst_reboot(void)
}
/*
+ * Moorestown does not have external NMI source nor port 0x61 to report
+ * NMI status. The possible NMI sources are from pmu as a result of NMI
+ * watchdog or lock debug. Reading io port 0x61 results in 0xff which
+ * misled NMI handler.
+ */
+static unsigned char mrst_get_nmi_reason(void)
+{
+ return 0;
+}
+
+/*
* Moorestown specific x86_init function overrides and early setup
* calls.
*/
@@ -297,6 +308,8 @@ void __init x86_mrst_early_setup(void)
x86_platform.calibrate_tsc = mrst_calibrate_tsc;
x86_platform.i8042_detect = mrst_i8042_detect;
x86_init.timers.wallclock_init = mrst_rtc_init;
+ x86_platform.get_nmi_reason = mrst_get_nmi_reason;
+
x86_init.pci.init = pci_mrst_init;
x86_init.pci.fixup_irqs = x86_init_noop;