1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 4867f4cc0938..fa486c5fbb02 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -287,6 +287,9 @@ 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;
 
+        /* Err to enabling backlight if no backlight block. */
+        dev_priv->vbt.backlight.present = true;
+
         backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT);
         if (!backlight_data)
                 return;
@@ -299,6 +302,13 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 
         entry = &backlight_data->data[panel_type];
 
+        dev_priv->vbt.backlight.present = entry->type == BDB_BACKLIGHT_TYPE_PWM;
+        if (!dev_priv->vbt.backlight.present) {
+                DRM_DEBUG_KMS("PWM backlight not present in VBT (type %u)\n",
+                              entry->type);
+                return;
+        }
+
         dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
         dev_priv->vbt.backlight.active_low_pwm = entry->active_low_pwm;
         DRM_DEBUG_KMS("VBT backlight PWM modulation frequency %u Hz, "