• Henrique de Moraes Holschuh's avatar
    thinkpad-acpi: rework brightness support · 0e501834
    Henrique de Moraes Holschuh authored
    Refactor and redesign the brightness control backend...
    
    In order to fix bugzilla #11750...
    
    Add a new brightness control mode: support direct NVRAM checkpointing
    of the backlight level (i.e. store directly to NVRAM without the need
    for UCMS calls), and use that together with the EC-based control.
    Disallow UCMS+EC, thus avoiding races with the SMM firmware.
    
    Switch the models that define HBRV (EC Brightness Value) in the DSDT
    to the new mode.  These are: T40-T43, R50-R52, R50e, R51e, X31-X41.
    
    Change the default for all other IBM ThinkPads to UCMS-only.  The
    Lenovo models already default to UCMS-only.
    Reported-by: default avatarAlexey Fisher <bug-track@fisher-privat.net>
    Signed-off-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    0e501834
thinkpad-acpi.txt 58.1 KB