So far for devices using an external PWM controller (devices using pwm_setup_backlight()), we have been hardcoding the minimum allowed PWM level to 0. But several of these devices specify a non 0 minimum setting in their VBT. Change pwm_setup_backlight() to use get_backlight_min_vbt() to get the minimum level. Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_panel.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index 14e611c92194..cb28b9908ca4 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -1925,8 +1925,8 @@ static int pwm_setup_backlight(struct intel_connector *connector, */ pwm_apply_args(panel->backlight.pwm); - panel->backlight.min = 0; /* 0% */ panel->backlight.max = 100; /* 100% */ + panel->backlight.min = get_backlight_min_vbt(connector); level = intel_panel_compute_brightness(connector, 100); ns = DIV_ROUND_UP(level * panel->backlight.pwm_period_ns, 100); @@ -1941,8 +1941,9 @@ static int pwm_setup_backlight(struct intel_connector *connector, level = DIV_ROUND_UP(pwm_get_duty_cycle(panel->backlight.pwm) * 100, panel->backlight.pwm_period_ns); - panel->backlight.level = - intel_panel_compute_brightness(connector, level); + level = intel_panel_compute_brightness(connector, level); + panel->backlight.level = clamp(level, panel->backlight.min, + panel->backlight.max); panel->backlight.enabled = panel->backlight.level != 0; drm_info(&dev_priv->drm, "Using %s PWM for LCD backlight control\n", -- 2.26.2
