• Alan Jenkins's avatar
    eeepc-laptop: Work around rfkill firmware bug · 978605c4
    Alan Jenkins authored
    1) Buggy firmware can change the RFKILL state by itself. This is easily
       detected.  The RFKILL API states that in such cases, we should call
       rfkill_force_state() to notify the core.
    
       I have reported the bug to Asus. I believe this is the right thing
       to do for robustness, even if this particular firmware bug is fixed.
    
    2) The same bug causes the wireless toggle key to be reported as 0x11
       instead of 0x10.  0x11 is otherwise unused, so it should be safe to
       add this as a new keycode.
    
    The bug is triggered by removing the laptop battery while hibernated.
    
    On resume, the wireless toggle key causes the firmware to toggle the
    wireless state itself.  (Also, the key is reported as 0x11 when the
    current wireless state is OFF).
    
    This is very poor behaviour because the OS can't predict whether the
    firmware is controlling the RFKILL state.
    
    Without this workaround, the bug means users have to press the wireless
    toggle key twice to enable, due to the OS/firmware conflict.  (Assuming
    rfkill-input or equivalent is being used).  The workaround avoids this.
    
    I believe that acpid scripts which toggle the value of the sysfs state file
    when the toggle key is pressed will be rendered ineffective by the bug,
    regardless of this workaround.  If they simply toggle the state, when the
    firmware has already toggled it, then you will never see a state change.
    
    Tested on "EEEPC 4G" only.
    Signed-off-by: default avatarAlan Jenkins <alan-jenkins@tuffmail.co.uk>
    Signed-off-by: default avatarCorentin Chary <corentincj@iksaif.net>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    978605c4
eeepc-laptop.c 24.6 KB