diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 2a897e174ed5..f729998979e6 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -284,6 +284,7 @@ struct intel_panel {
 		bool combination_mode;	/* gen 2/4 only */
 		bool active_low_pwm;
 		bool alternate_pwm_increment;	/* lpt+ */
+		bool cpu_mode; /* lpt */
 
 		/* PWM chip */
 		bool util_pin_active_low;	/* bxt+ */
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index e6cd7b55c018..106d97618e03 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -460,18 +460,22 @@ static u32 intel_panel_compute_brightness(struct intel_connector *connector,
 	return val;
 }
 
-static u32 lpt_get_backlight(struct intel_connector *connector)
+static u32 pch_get_backlight(struct intel_connector *connector)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
 
-	return I915_READ(BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
+	return I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
 }
 
-static u32 pch_get_backlight(struct intel_connector *connector)
+static u32 lpt_get_backlight(struct intel_connector *connector)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	struct intel_panel *panel = &connector->panel;
 
-	return I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
+	if (panel->backlight.cpu_mode)
+		return pch_get_backlight(connector);
+
+	return I915_READ(BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
 }
 
 static u32 i9xx_get_backlight(struct intel_connector *connector)
@@ -657,9 +661,12 @@ static void lpt_disable_backlight(const struct drm_connector_state *old_conn_sta
 {
 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	struct intel_panel *panel = &connector->panel;
+
 	u32 tmp;
 
 	intel_panel_actually_set_backlight(old_conn_state, 0);
+	panel->backlight.cpu_mode = false;
 
 	/*
 	 * Although we don't support or enable CPU PWM with LPT/SPT based
@@ -806,6 +813,8 @@ static void lpt_enable_backlight(const struct intel_crtc_state *crtc_state,
 	struct intel_panel *panel = &connector->panel;
 	u32 pch_ctl1, pch_ctl2, schicken;
 
+	panel->backlight.cpu_mode = false;
+
 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
 		DRM_DEBUG_KMS("pch backlight already enabled\n");
@@ -1507,13 +1516,19 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus
 
 	panel->backlight.min = get_backlight_min_vbt(connector);
 
+	panel->backlight.enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE;
+
+	if (panel->backlight.enabled && HAS_PCH_LPT(dev_priv)) {
+		u32 cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
+
+		panel->backlight.cpu_mode = cpu_ctl2 & BLM_PWM_ENABLE;
+	}
+
 	val = lpt_get_backlight(connector);
 	val = intel_panel_compute_brightness(connector, val);
 	panel->backlight.level = clamp(val, panel->backlight.min,
 				       panel->backlight.max);
 
-	panel->backlight.enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE;
-
 	return 0;
 }