• Thomas Renninger's avatar
    cpufreq / ACPI: Fix not loading acpi-cpufreq driver regression · c4686c71
    Thomas Renninger authored
    Commit d640113f introduced a regression on SMP
    systems where the processor core with ACPI id zero is disabled
    (typically should be the case because of hyperthreading).
    The regression got spread through stable kernels.
    On 3.0.X it got introduced via 3.0.18.
    
    Such platforms may be rare, but do exist.
    Look out for a disabled processor with acpi_id 0 in dmesg:
    ACPI: LAPIC (acpi_id[0x00] lapic_id[0x10] disabled)
    
    This problem has been observed on a:
    HP Proliant BL280c G6 blade
    
    This patch restricts the introduced workaround to platforms
    with nr_cpu_ids <= 1.
    Signed-off-by: default avatarThomas Renninger <trenn@suse.de>
    CC: stable@vger.kernel.org
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    c4686c71
processor_core.c 9.01 KB