Revert "drm/i915: Parsing LFP brightness control from VBT"

This reverts commit 371abae8.

This data seems unreliable and causing many issues and blocking other
teams and feature implementation. Safest way is to revert that for now.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88081
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88039
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=87671
Cc: Vandana Kannan <vandana.kannan@intel.com>
Cc: Deepak M <m.deepak@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Kristian Høgsberg <hoegsberg@gmail.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1408,7 +1408,6 @@ struct intel_vbt_data {
 		bool present;
 		bool active_low_pwm;
 		u8 min_brightness;	/* min_brightness/255 of max */
-		u8 controller;		/* brightness controller number */
 	} backlight;
 
 	/* MIPI DSI */

drivers/gpu/drm/i915/intel_bios.c

@@ -314,7 +314,6 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 {
 	const struct bdb_lfp_backlight_data *backlight_data;
 	const struct bdb_lfp_backlight_data_entry *entry;
-	const struct bdb_lfp_backlight_control_data *bl_ctrl_data;
 
 	backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
 	if (!backlight_data)
@@ -327,7 +326,6 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 	}
 
 	entry = &backlight_data->data[panel_type];
-	bl_ctrl_data = &backlight_data->blc_ctl[panel_type];
 
 	dev_priv->vbt.backlight.present = entry->type == BDB_BACKLIGHT_TYPE_PWM;
 	if (!dev_priv->vbt.backlight.present) {
@@ -339,30 +337,12 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 	dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
 	dev_priv->vbt.backlight.active_low_pwm = entry->active_low_pwm;
 	dev_priv->vbt.backlight.min_brightness = entry->min_brightness;
-
-	dev_priv->vbt.backlight.controller = 0;
-	if (bdb->version >= 191) {
-		dev_priv->vbt.backlight.present =
-				bl_ctrl_data->pin == BLC_CONTROL_PIN_DDI;
-		if (!dev_priv->vbt.backlight.present) {
-			DRM_DEBUG_KMS("BL control pin is not DDI (pin %u)\n",
-					bl_ctrl_data->pin);
-			return;
-		}
-		if (bl_ctrl_data->controller == 1)
-			dev_priv->vbt.backlight.controller =
-				bl_ctrl_data->controller;
-	}
-
 	DRM_DEBUG_KMS("VBT backlight PWM modulation frequency %u Hz, "
 		      "active %s, min brightness %u, level %u\n",
 		      dev_priv->vbt.backlight.pwm_freq_hz,
 		      dev_priv->vbt.backlight.active_low_pwm ? "low" : "high",
 		      dev_priv->vbt.backlight.min_brightness,
 		      backlight_data->level[panel_type]);
-
-	DRM_DEBUG_KMS("VBT BL controller %u\n",
-		dev_priv->vbt.backlight.controller);
 }
 
 /* Try to find sdvo panel data */

drivers/gpu/drm/i915/intel_bios.h

@@ -402,21 +402,10 @@ struct bdb_lfp_backlight_data_entry {
 	u8 obsolete3;
 } __packed;
 
-#define BLC_CONTROL_PIN_PMIC		0
-#define BLC_CONTROL_PIN_LPSS_PWM	1
-#define BLC_CONTROL_PIN_DDI		2
-#define BLC_CONTROL_PIN_CABC		3
-
-struct bdb_lfp_backlight_control_data {
-	u8 controller:4;
-	u8 pin:4;
-} __packed;
-
 struct bdb_lfp_backlight_data {
 	u8 entry_size;
 	struct bdb_lfp_backlight_data_entry data[16];
 	u8 level[16];
-	struct bdb_lfp_backlight_control_data blc_ctl[16];
 } __packed;
 
 struct aimdb_header {