• Jacob Pan's avatar
    x86/mrst: Avoid reporting wrong nmi status · 064a59b6
    Jacob Pan authored
    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: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    [hand applied]
    Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
    064a59b6
nmi.c 10.4 KB