[PATCH] Revert nmi_known_cpu() check during boot option parsing

Commit f2802e7f571c05f9a901b1f5bd144aa730ccc88e and its x86 version
(b7471c6da94d30d3deadc55986cc38d1ff57f9ca) adds nmi_known_cpu() check
while parsing boot options in x86_64 and i386.

With that, "nmi_watchdog=2" stops working for me on Intel Core 2 CPU
based system.

The problem is, setup_nmi_watchdog is called while parsing the boot
option and identify_cpu is not done yet.  So, the return value of
nmi_known_cpu() is not valid at this point.

So revert that check.  This should not have any adverse effect as the
nmi_known_cpu() check is done again later in enable_lapic_nmi_watchdog().

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 1 insertions, 9 deletions

diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index a5e34d655965..1a6f8bb8881c 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -310,13 +310,7 @@ static int __init setup_nmi_watchdog(char *str)
 
         if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
                 return 0;
-        /*
-         * If any other x86 CPU has a local APIC, then
-         * please test the NMI stuff there and send me the
-         * missing bits. Right now Intel P6/P4 and AMD K7 only.
-         */
-        if ((nmi == NMI_LOCAL_APIC) && (nmi_known_cpu() == 0))
-                return 0;  /* no lapic support */
+
         nmi_watchdog = nmi;
         return 1;
 }
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 186aebbae32d..9cb42ecb7f89 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -302,8 +302,6 @@ int __init setup_nmi_watchdog(char *str)
         if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
                 return 0;
 
-        if ((nmi == NMI_LOCAL_APIC) && (nmi_known_cpu() == 0))
-                return 0;  /* no lapic support */
         nmi_watchdog = nmi;
         return 1;
 }