drm/i915: Fix pipe enabled mask for pipe C in WM calculations

Fix the incorrect enabled pipes mask for pipe C in the WM calculations.

Additionally, in an effort to make the code easier to understand,
populate the mask with 1 << PIPE_[ABC] instead of raw numbers.

v2: Use 1 << PIPE_[ABC] (ickle/danvet)
v3: Pass PIPE_[ABC] to g4x_compute_wm0() (ickle)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -1301,17 +1301,17 @@ static void valleyview_update_wm(struct drm_device *dev)
 
 	vlv_update_drain_latency(dev);
 
-	if (g4x_compute_wm0(dev, 0,
+	if (g4x_compute_wm0(dev, PIPE_A,
 			    &valleyview_wm_info, latency_ns,
 			    &valleyview_cursor_wm_info, latency_ns,
 			    &planea_wm, &cursora_wm))
-		enabled |= 1;
+		enabled |= 1 << PIPE_A;
 
-	if (g4x_compute_wm0(dev, 1,
+	if (g4x_compute_wm0(dev, PIPE_B,
 			    &valleyview_wm_info, latency_ns,
 			    &valleyview_cursor_wm_info, latency_ns,
 			    &planeb_wm, &cursorb_wm))
-		enabled |= 2;
+		enabled |= 1 << PIPE_B;
 
 	if (single_plane_enabled(enabled) &&
 	    g4x_compute_srwm(dev, ffs(enabled) - 1,
@@ -1357,17 +1357,17 @@ static void g4x_update_wm(struct drm_device *dev)
 	int plane_sr, cursor_sr;
 	unsigned int enabled = 0;
 
-	if (g4x_compute_wm0(dev, 0,
+	if (g4x_compute_wm0(dev, PIPE_A,
 			    &g4x_wm_info, latency_ns,
 			    &g4x_cursor_wm_info, latency_ns,
 			    &planea_wm, &cursora_wm))
-		enabled |= 1;
+		enabled |= 1 << PIPE_A;
 
-	if (g4x_compute_wm0(dev, 1,
+	if (g4x_compute_wm0(dev, PIPE_B,
 			    &g4x_wm_info, latency_ns,
 			    &g4x_cursor_wm_info, latency_ns,
 			    &planeb_wm, &cursorb_wm))
-		enabled |= 2;
+		enabled |= 1 << PIPE_B;
 
 	if (single_plane_enabled(enabled) &&
 	    g4x_compute_srwm(dev, ffs(enabled) - 1,
@@ -1716,7 +1716,7 @@ static void ironlake_update_wm(struct drm_device *dev)
 	unsigned int enabled;
 
 	enabled = 0;
-	if (g4x_compute_wm0(dev, 0,
+	if (g4x_compute_wm0(dev, PIPE_A,
 			    &ironlake_display_wm_info,
 			    ILK_LP0_PLANE_LATENCY,
 			    &ironlake_cursor_wm_info,
@@ -1727,10 +1727,10 @@ static void ironlake_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe A -"
 			      " plane %d, " "cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 1;
+		enabled |= 1 << PIPE_A;
 	}
 
-	if (g4x_compute_wm0(dev, 1,
+	if (g4x_compute_wm0(dev, PIPE_B,
 			    &ironlake_display_wm_info,
 			    ILK_LP0_PLANE_LATENCY,
 			    &ironlake_cursor_wm_info,
@@ -1741,7 +1741,7 @@ static void ironlake_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe B -"
 			      " plane %d, cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 2;
+		enabled |= 1 << PIPE_B;
 	}
 
 	/*
@@ -1801,7 +1801,7 @@ static void sandybridge_update_wm(struct drm_device *dev)
 	unsigned int enabled;
 
 	enabled = 0;
-	if (g4x_compute_wm0(dev, 0,
+	if (g4x_compute_wm0(dev, PIPE_A,
 			    &sandybridge_display_wm_info, latency,
 			    &sandybridge_cursor_wm_info, latency,
 			    &plane_wm, &cursor_wm)) {
@@ -1812,10 +1812,10 @@ static void sandybridge_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe A -"
 			      " plane %d, " "cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 1;
+		enabled |= 1 << PIPE_A;
 	}
 
-	if (g4x_compute_wm0(dev, 1,
+	if (g4x_compute_wm0(dev, PIPE_B,
 			    &sandybridge_display_wm_info, latency,
 			    &sandybridge_cursor_wm_info, latency,
 			    &plane_wm, &cursor_wm)) {
@@ -1826,7 +1826,7 @@ static void sandybridge_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe B -"
 			      " plane %d, cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 2;
+		enabled |= 1 << PIPE_B;
 	}
 
 	/*
@@ -1904,7 +1904,7 @@ static void ivybridge_update_wm(struct drm_device *dev)
 	unsigned int enabled;
 
 	enabled = 0;
-	if (g4x_compute_wm0(dev, 0,
+	if (g4x_compute_wm0(dev, PIPE_A,
 			    &sandybridge_display_wm_info, latency,
 			    &sandybridge_cursor_wm_info, latency,
 			    &plane_wm, &cursor_wm)) {
@@ -1915,10 +1915,10 @@ static void ivybridge_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe A -"
 			      " plane %d, " "cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 1;
+		enabled |= 1 << PIPE_A;
 	}
 
-	if (g4x_compute_wm0(dev, 1,
+	if (g4x_compute_wm0(dev, PIPE_B,
 			    &sandybridge_display_wm_info, latency,
 			    &sandybridge_cursor_wm_info, latency,
 			    &plane_wm, &cursor_wm)) {
@@ -1929,10 +1929,10 @@ static void ivybridge_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe B -"
 			      " plane %d, cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 2;
+		enabled |= 1 << PIPE_B;
 	}
 
-	if (g4x_compute_wm0(dev, 2,
+	if (g4x_compute_wm0(dev, PIPE_C,
 			    &sandybridge_display_wm_info, latency,
 			    &sandybridge_cursor_wm_info, latency,
 			    &plane_wm, &cursor_wm)) {
@@ -1943,7 +1943,7 @@ static void ivybridge_update_wm(struct drm_device *dev)
 		DRM_DEBUG_KMS("FIFO watermarks For pipe C -"
 			      " plane %d, cursor: %d\n",
 			      plane_wm, cursor_wm);
-		enabled |= 3;
+		enabled |= 1 << PIPE_C;
 	}
 
 	/*