• Thomas Gleixner's avatar
    x86/tsc: Limit the adjust value further · 8c9b9d87
    Thomas Gleixner authored
    Adjust value 0x80000000 and other values larger than that render the TSC
    deadline timer disfunctional.
    
    We have not yet any information about this from Intel, but experimentation
    clearly proves that this is a 32/64 bit and sign extension issue.
    
    If adjust values larger than that are actually required, which might be the
    case for physical CPU hotplug, then we need to disable the deadline timer
    on the affected package/CPUs and use the local APIC timer instead.
    
    That requires some surgery in the APIC setup code, so we just limit the
    ADJUST register value into the known to work range for now and revisit this
    when Intel comes forth with proper information.
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: Roland Scheidegger <rscheidegger_lists@hispeed.ch>
    Cc: Bruce Schlobohm <bruce.schlobohm@intel.com>
    Cc: Kevin Stanton <kevin.b.stanton@intel.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Borislav Petkov <bp@alien8.de>
    8c9b9d87
tsc_sync.c 12.7 KB