• Lv Zheng's avatar
    ACPICA: Add boot option to disable auto return object repair · 4dde507f
    Lv Zheng authored
    Sometimes, there might be bugs caused by unexpected AML which is compliant
    to the Windows but not compliant to the Linux implementation.
    
    There is a predefined validation mechanism implemented in ACPICA to repair
    the unexpected AML evaluation results that are caused by the unexpected
    AMLs.  For example, BIOS may return misorder _CST result and the repair
    mechanism can make an ascending order on the returned _CST package object
    based on the C-state type.
    This mechanism is quite useful to implement an AML interpreter with better
    compliance with the real world where Windows is the de-facto standard and
    BIOS codes are only tested on one platform thus not compliant to the
    ACPI specification.
    
    But if a compliance issue hasn't been figured out yet, it will be
    difficult for developers to identify if the unexpected evaluation result
    is caused by this mechanism or by the AML interpreter.
    For example, _PR0 is expected to be a control method, but BIOS may use
    Package: "Name(_PR0, Package(1) {P1PR})".
    This boot option can disable the predefined validation mechanism so that
    developers can make sure the root cause comes from the parser/executer.
    
    This patch adds a new kernel parameter to disable this feature.
    
    A build test has been made on a Dell Inspiron mini 1100 (i386 z530)
    machine when this patch is applied and the corresponding boot test is
    performed w/ or w/o the new kernel parameter specified.
    
    References: https://bugzilla.kernel.org/show_bug.cgi?id=67901Tested-by: default avatarFabian Wehning <fabian.wehning@googlemail.com>
    Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    4dde507f
kernel-parameters.txt 125 KB