diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d63a731ef60bf5d018fa8c2d9d35021e7762707e..a1268d706c5e13251065cbc92809e37298b54f3d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -698,7 +698,8 @@ struct drm_i915_display_funcs {
 			  struct intel_cdclk_state *cdclk_state);
 	void (*set_cdclk)(struct drm_i915_private *dev_priv,
 			  const struct intel_cdclk_state *cdclk_state);
-	int (*get_fifo_size)(struct drm_i915_private *dev_priv, int plane);
+	int (*get_fifo_size)(struct drm_i915_private *dev_priv,
+			     enum i9xx_plane_id i9xx_plane);
 	int (*compute_pipe_wm)(struct intel_crtc_state *cstate);
 	int (*compute_intermediate_wm)(struct drm_device *dev,
 				       struct intel_crtc *intel_crtc,
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index ce5cd75b81301ca51b6f476dd234fcb9123a30df..e445ec17483178fcc3bcdea41a06e42e0c90a9f1 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -512,38 +512,41 @@ static void vlv_get_fifo_size(struct intel_crtc_state *crtc_state)
 	fifo_state->plane[PLANE_CURSOR] = 63;
 }
 
-static int i9xx_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
+static int i9xx_get_fifo_size(struct drm_i915_private *dev_priv,
+			      enum i9xx_plane_id i9xx_plane)
 {
 	uint32_t dsparb = I915_READ(DSPARB);
 	int size;
 
 	size = dsparb & 0x7f;
-	if (plane)
+	if (i9xx_plane == PLANE_B)
 		size = ((dsparb >> DSPARB_CSTART_SHIFT) & 0x7f) - size;
 
-	DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
-		      plane ? "B" : "A", size);
+	DRM_DEBUG_KMS("FIFO size - (0x%08x) %c: %d\n",
+		      dsparb, plane_name(i9xx_plane), size);
 
 	return size;
 }
 
-static int i830_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
+static int i830_get_fifo_size(struct drm_i915_private *dev_priv,
+			      enum i9xx_plane_id i9xx_plane)
 {
 	uint32_t dsparb = I915_READ(DSPARB);
 	int size;
 
 	size = dsparb & 0x1ff;
-	if (plane)
+	if (i9xx_plane == PLANE_B)
 		size = ((dsparb >> DSPARB_BEND_SHIFT) & 0x1ff) - size;
 	size >>= 1; /* Convert to cachelines */
 
-	DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
-		      plane ? "B" : "A", size);
+	DRM_DEBUG_KMS("FIFO size - (0x%08x) %c: %d\n",
+		      dsparb, plane_name(i9xx_plane), size);
 
 	return size;
 }
 
-static int i845_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
+static int i845_get_fifo_size(struct drm_i915_private *dev_priv,
+			      enum i9xx_plane_id i9xx_plane)
 {
 	uint32_t dsparb = I915_READ(DSPARB);
 	int size;
@@ -551,9 +554,8 @@ static int i845_get_fifo_size(struct drm_i915_private *dev_priv, int plane)
 	size = dsparb & 0x7f;
 	size >>= 2; /* Convert to cachelines */
 
-	DRM_DEBUG_KMS("FIFO size - (0x%08x) %s: %d\n", dsparb,
-		      plane ? "B" : "A",
-		      size);
+	DRM_DEBUG_KMS("FIFO size - (0x%08x) %c: %d\n",
+		      dsparb, plane_name(i9xx_plane), size);
 
 	return size;
 }
@@ -2277,8 +2279,8 @@ static void i9xx_update_wm(struct intel_crtc *unused_crtc)
 	else
 		wm_info = &i830_a_wm_info;
 
-	fifo_size = dev_priv->display.get_fifo_size(dev_priv, 0);
-	crtc = intel_get_crtc_for_plane(dev_priv, 0);
+	fifo_size = dev_priv->display.get_fifo_size(dev_priv, PLANE_A);
+	crtc = intel_get_crtc_for_plane(dev_priv, PLANE_A);
 	if (intel_crtc_active(crtc)) {
 		const struct drm_display_mode *adjusted_mode =
 			&crtc->config->base.adjusted_mode;
@@ -2304,8 +2306,8 @@ static void i9xx_update_wm(struct intel_crtc *unused_crtc)
 	if (IS_GEN2(dev_priv))
 		wm_info = &i830_bc_wm_info;
 
-	fifo_size = dev_priv->display.get_fifo_size(dev_priv, 1);
-	crtc = intel_get_crtc_for_plane(dev_priv, 1);
+	fifo_size = dev_priv->display.get_fifo_size(dev_priv, PLANE_B);
+	crtc = intel_get_crtc_for_plane(dev_priv, PLANE_B);
 	if (intel_crtc_active(crtc)) {
 		const struct drm_display_mode *adjusted_mode =
 			&crtc->config->base.adjusted_mode;
@@ -2417,7 +2419,7 @@ static void i845_update_wm(struct intel_crtc *unused_crtc)
 	adjusted_mode = &crtc->config->base.adjusted_mode;
 	planea_wm = intel_calculate_wm(adjusted_mode->crtc_clock,
 				       &i845_wm_info,
-				       dev_priv->display.get_fifo_size(dev_priv, 0),
+				       dev_priv->display.get_fifo_size(dev_priv, PLANE_A),
 				       4, pessimal_latency_ns);
 	fwater_lo = I915_READ(FW_BLC) & ~0xfff;
 	fwater_lo |= (3<<8) | planea_wm;