[PATCH 2/4] drm/i915: add plane enable/disable functions

[Jesse Barnes <jbarnes@virtuousgeek.org>]

Add plane enable/disable functions to prevent duplicated code and allow
us to easily check for plane enable/disable requirements (such as pipe
enable).

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_reg.h      |    5 +-
 drivers/gpu/drm/i915/intel_display.c |  123 +++++++++++++++++++--------------
 2 files changed, 74 insertions(+), 54 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2b6cafb..796dee5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2527,9 +2527,10 @@
 #define   DISPPLANE_32BPP_30BIT_NO_ALPHA	(0xa<<26)
 #define   DISPPLANE_STEREO_ENABLE		(1<<25)
 #define   DISPPLANE_STEREO_DISABLE		0
-#define   DISPPLANE_SEL_PIPE_MASK		(1<<24)
+#define   DISPPLANE_SEL_PIPE_SHIFT		24
+#define   DISPPLANE_SEL_PIPE_MASK		(3<<DISPPLANE_SEL_PIPE_SHIFT)
 #define   DISPPLANE_SEL_PIPE_A			0
-#define   DISPPLANE_SEL_PIPE_B			(1<<24)
+#define   DISPPLANE_SEL_PIPE_B			(1<<DISPPLANE_SEL_PIPE_SHIFT)
 #define   DISPPLANE_SRC_KEY_ENABLE		(1<<22)
 #define   DISPPLANE_SRC_KEY_DISABLE		0
 #define   DISPPLANE_LINE_DOUBLE			(1<<20)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 559e342..800514d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1086,6 +1086,19 @@ static void assert_pll(struct drm_i915_private *dev_priv, enum pipe pipe,
 #define assert_pll_enabled(d, p) assert_pll(d, p, on)
 #define assert_pll_disabled(d, p) assert_pll(d, p, off)
 
+static void assert_pipe_enabled(struct drm_i915_private *dev_priv,
+				enum pipe pipe)
+{
+	int reg;
+	u32 val;
+
+	reg = PIPECONF(pipe);
+	val = I915_READ(reg);
+	WARN(!(val & PIPECONF_ENABLE),
+	     "pipe %c assertion failure, should be active but is disabled\n",
+	     pipe ? 'B' : 'A');
+}
+
 static void assert_plane_enabled(struct drm_i915_private *dev_priv,
 				 enum plane plane)
 {
@@ -1188,6 +1201,55 @@ static void intel_disable_pipe(struct drm_i915_private *dev_priv,
 	intel_wait_for_pipe_off(dev_priv->dev, pipe);
 }
 
+/**
+ * intel_enable_plane - enable a display plane on a given pipe
+ * @dev_priv: i915 private structure
+ * @plane: plane to enable
+ * @pipe: pipe being fed
+ *
+ * Enable @plane on @pipe, making sure that @pipe is running first.
+ */
+static void intel_enable_plane(struct drm_i915_private *dev_priv,
+			       enum plane plane, enum pipe pipe)
+{
+	int reg;
+	u32 val;
+
+	/* If the pipe isn't enabled, we can't pump pixels and may hang */
+	assert_pipe_enabled(dev_priv, pipe);
+
+	reg = DSPCNTR(plane);
+	val = I915_READ(reg);
+	val |= DISPLAY_PLANE_ENABLE;
+	I915_WRITE(reg, val);
+	POSTING_READ(reg);
+	intel_wait_for_vblank(dev_priv->dev, pipe);
+}
+
+/**
+ * intel_disable_plane - disable a display plane
+ * @dev_priv: i915 private structure
+ * @plane: plane to disable
+ * @pipe: pipe consuming the data
+ *
+ * Disable @plane; should be an independent operation.
+ */
+static void intel_disable_plane(struct drm_i915_private *dev_priv,
+				enum plane plane, enum pipe pipe)
+{
+	int reg;
+	u32 val;
+
+	reg = DSPCNTR(plane);
+	val = I915_READ(reg);
+	val &= ~DISPLAY_PLANE_ENABLE;
+	I915_WRITE(reg, val);
+	POSTING_READ(reg);
+	reg = DSPADDR(plane);
+	I915_WRITE(reg, I915_READ(reg)); /* trigger an update */
+	intel_wait_for_vblank(dev_priv->dev, pipe);
+}
+
 static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
 {
 	struct drm_device *dev = crtc->dev;
@@ -2112,14 +2174,6 @@ static void ironlake_fdi_enable(struct drm_crtc *crtc)
 	}
 }
 
-static void intel_flush_display_plane(struct drm_device *dev,
-				      int plane)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 reg = DSPADDR(plane);
-	I915_WRITE(reg, I915_READ(reg));
-}
-
 /*
  * When we disable a pipe, we need to clear any pending scanline wait events
  * to avoid hanging the ring, which we assume we are waiting on.
@@ -2193,14 +2247,7 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
 	}
 
 	intel_enable_pipe(dev_priv, pipe);
-
-	/* configure and enable CPU plane */
-	reg = DSPCNTR(plane);
-	temp = I915_READ(reg);
-	if ((temp & DISPLAY_PLANE_ENABLE) == 0) {
-		I915_WRITE(reg, temp | DISPLAY_PLANE_ENABLE);
-		intel_flush_display_plane(dev, plane);
-	}
+	intel_enable_plane(dev_priv, plane, pipe);
 
 	/* For PCH output, training FDI link */
 	if (IS_GEN6(dev))
@@ -2308,13 +2355,7 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 	drm_vblank_off(dev, pipe);
 	intel_crtc_update_cursor(crtc, false);
 
-	/* Disable display plane */
-	reg = DSPCNTR(plane);
-	temp = I915_READ(reg);
-	if (temp & DISPLAY_PLANE_ENABLE) {
-		I915_WRITE(reg, temp & ~DISPLAY_PLANE_ENABLE);
-		intel_flush_display_plane(dev, plane);
-	}
+	intel_disable_plane(dev_priv, plane, pipe);
 
 	if (dev_priv->cfb_plane == plane &&
 	    dev_priv->display.disable_fbc)
@@ -2519,14 +2560,7 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc)
 	}
 
 	intel_enable_pipe(dev_priv, pipe);
-
-	/* Enable the plane */
-	reg = DSPCNTR(plane);
-	temp = I915_READ(reg);
-	if ((temp & DISPLAY_PLANE_ENABLE) == 0) {
-		I915_WRITE(reg, temp | DISPLAY_PLANE_ENABLE);
-		intel_flush_display_plane(dev, plane);
-	}
+	intel_enable_plane(dev_priv, plane, pipe);
 
 	intel_crtc_load_lut(crtc);
 	intel_update_fbc(dev);
@@ -2558,18 +2592,7 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
 	    dev_priv->display.disable_fbc)
 		dev_priv->display.disable_fbc(dev);
 
-	/* Disable display plane */
-	reg = DSPCNTR(plane);
-	temp = I915_READ(reg);
-	if (temp & DISPLAY_PLANE_ENABLE) {
-		I915_WRITE(reg, temp & ~DISPLAY_PLANE_ENABLE);
-		/* Flush the plane changes */
-		intel_flush_display_plane(dev, plane);
-
-		/* Wait for vblank for the disable to take effect */
-		if (IS_GEN2(dev))
-			intel_wait_for_vblank(dev, pipe);
-	}
+	intel_disable_plane(dev_priv, plane, pipe);
 
 	/* Don't disable pipe A or pipe A PLLs if needed */
 	if (pipe == 0 && (dev_priv->quirks & QUIRK_PIPEA_FORCE))
@@ -4315,10 +4338,8 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 			pipeconf &= ~PIPECONF_DOUBLE_WIDE;
 	}
 
-	if (!HAS_PCH_SPLIT(dev)) {
-		dspcntr |= DISPLAY_PLANE_ENABLE;
+	if (!HAS_PCH_SPLIT(dev))
 		dpll |= DPLL_VCO_ENABLE;
-	}
 
 	DRM_DEBUG_KMS("Mode for pipe %c:\n", pipe == 0 ? 'A' : 'B');
 	drm_mode_debug_printmodeline(mode);
@@ -4539,6 +4560,9 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 	}
 
 	I915_WRITE(DSPCNTR(plane), dspcntr);
+	POSTING_READ(DSPCNTR(plane));
+	if (!HAS_PCH_SPLIT(dev))
+		intel_enable_plane(dev_priv, plane, pipe);
 
 	ret = intel_pipe_set_base(crtc, x, y, old_fb);
 
@@ -5676,12 +5700,7 @@ static void intel_sanitize_modesetting(struct drm_device *dev,
 	pipe = !pipe;
 
 	/* Disable the plane and wait for it to stop reading from the pipe. */
-	I915_WRITE(reg, val & ~DISPLAY_PLANE_ENABLE);
-	intel_flush_display_plane(dev, plane);
-
-	if (IS_GEN2(dev))
-		intel_wait_for_vblank(dev, pipe);
-
+	intel_disable_plane(dev_priv, plane, pipe);
 	intel_disable_pipe(dev_priv, pipe);
 }
 
-- 
1.7.0.4