There are some panel that (1) does not support display backlight enable via AUX (2) support display backlight adjustment via AUX (3) support display backlight enable via eDP BL_ENABLE pin The current driver required that (1) must be support to enable (2). This patch drops that requirement. Signed-off-by: Puthikorn Voravootivat <puthik@chromium.org> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170523223805.46372-2-puthik@chromium.org