• Henrique de Moraes Holschuh's avatar
    thinkpad-acpi: restrict access to some firmware LEDs · a4d5effc
    Henrique de Moraes Holschuh authored
    Some of the ThinkPad LEDs indicate critical conditions that can cause
    data loss or cause hardware damage when ignored (e.g. force-ejecting
    a powered up bay; ignoring a failing battery, or empty battery; force-
    undocking with the dock buses still active, etc).
    
    On almost all ThinkPads, LED access is write-only, and the firmware
    usually does fire-and-forget signaling on them, so you effectively
    lose whatever message the firmware was trying to convey to the user
    when you override the LED state, without any chance to restore it.
    
    Restrict access to all LEDs that can convey important alarms, or that
    could mislead the user into incorrectly operating the hardware.  This
    will make the Lenovo engineers less unhappy about the whole issue.
    
    Allow users that really want it to still control all LEDs, it is the
    unaware user that we have to worry about.
    Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    a4d5effc
thinkpad-acpi.txt 57.7 KB