[Intel-gfx] [PATCH] drm/i915: set min brightness for aux backlight interface.

[Lee Shawn C]

Min brightness level for aux backlight interface is always zero.
Driver should refer to VBT's setting to configure proper minimum
level just like PWM backlight interface.

Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Cc: Lyude Paul <lyude at redhat.com>
Cc: Cooper Chiou <cooper.chiou at intel.com>

Signed-off-by: Lee Shawn C <shawn.c.lee at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 2 +-
 drivers/gpu/drm/i915/display/intel_panel.c            | 2 +-
 drivers/gpu/drm/i915/display/intel_panel.h            | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 4f8337c7fd2e..efd8fa155105 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -571,7 +571,7 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
 	if (!panel->backlight.max)
 		return -ENODEV;
 
-	panel->backlight.min = 0;
+	panel->backlight.min = get_backlight_min_vbt(connector);
 	panel->backlight.level = intel_dp_aux_vesa_get_backlight(connector, pipe);
 	panel->backlight.enabled = intel_dp_aux_vesa_backlight_dpcd_mode(connector) &&
 				   panel->backlight.level != 0;
diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c
index 551fcaa77c2c..6d58ec192a04 100644
--- a/drivers/gpu/drm/i915/display/intel_panel.c
+++ b/drivers/gpu/drm/i915/display/intel_panel.c
@@ -1614,7 +1614,7 @@ static u32 get_backlight_max_vbt(struct intel_connector *connector)
 /*
  * Note: The setup hooks can't assume pipe is set!
  */
-static u32 get_backlight_min_vbt(struct intel_connector *connector)
+u32 get_backlight_min_vbt(struct intel_connector *connector)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
 	struct intel_panel *panel = &connector->panel;
diff --git a/drivers/gpu/drm/i915/display/intel_panel.h b/drivers/gpu/drm/i915/display/intel_panel.h
index 1d340f77bffc..63da4e355585 100644
--- a/drivers/gpu/drm/i915/display/intel_panel.h
+++ b/drivers/gpu/drm/i915/display/intel_panel.h
@@ -53,6 +53,7 @@ void intel_panel_set_pwm_level(const struct drm_connector_state *conn_state, u32
 u32 intel_panel_invert_pwm_level(struct intel_connector *connector, u32 level);
 u32 intel_panel_backlight_level_to_pwm(struct intel_connector *connector, u32 level);
 u32 intel_panel_backlight_level_from_pwm(struct intel_connector *connector, u32 val);
+u32 get_backlight_min_vbt(struct intel_connector *connector);
 
 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
 int intel_backlight_device_register(struct intel_connector *connector);
-- 
2.17.1