The i915 driver failed to manage the backlight control: [ 4.874966] [drm:pwm_setup_backlight [i915]] *ERROR* Failed to own the pwm chip [ 4.875237] [drm:intel_panel_setup_backlight [i915]] failed to setup backlight for connector DSI-1 It seems that a few kernel configs are disabled for Atom SoC, e.g. CONFIG_INTEL_SOC_PMIC=y CONFIG_PWM_CRC=y might be needed. Are you building a kernel manually?