drm/i915: factor out FDI disable and add FDI assertions

Factor out the FDI disable function (make it a mirror of
ironlake_fdi_enable) and add some FDI related assertions to the FDI
training code (we need an active pipe & plane before we start
transmitting bits).

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/intel_display.c

@@ -2237,8 +2237,13 @@ static void ironlake_fdi_link_train(struct drm_crtc *crtc)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
+	int plane = intel_crtc->plane;
 	u32 reg, temp, tries;
 
+	/* FDI needs bits from pipe & plane first */
+	assert_pipe_enabled(dev_priv, pipe);
+	assert_plane_enabled(dev_priv, plane);
+
 	/* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
 	   for train result */
 	reg = FDI_RX_IMR(pipe);
@@ -2487,6 +2492,60 @@ static void ironlake_fdi_enable(struct drm_crtc *crtc)
 	}
 }
 
+static void ironlake_fdi_disable(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+	u32 reg, temp;
+
+	/* disable CPU FDI tx and PCH FDI rx */
+	reg = FDI_TX_CTL(pipe);
+	temp = I915_READ(reg);
+	I915_WRITE(reg, temp & ~FDI_TX_ENABLE);
+	POSTING_READ(reg);
+
+	reg = FDI_RX_CTL(pipe);
+	temp = I915_READ(reg);
+	temp &= ~(0x7 << 16);
+	temp |= (I915_READ(PIPECONF(pipe)) & PIPE_BPC_MASK) << 11;
+	I915_WRITE(reg, temp & ~FDI_RX_ENABLE);
+
+	POSTING_READ(reg);
+	udelay(100);
+
+	/* Ironlake workaround, disable clock pointer after downing FDI */
+	if (HAS_PCH_IBX(dev))
+		I915_WRITE(FDI_RX_CHICKEN(pipe),
+			   I915_READ(FDI_RX_CHICKEN(pipe) &
+				     ~FDI_RX_PHASE_SYNC_POINTER_ENABLE));
+
+	/* still set train pattern 1 */
+	reg = FDI_TX_CTL(pipe);
+	temp = I915_READ(reg);
+	temp &= ~FDI_LINK_TRAIN_NONE;
+	temp |= FDI_LINK_TRAIN_PATTERN_1;
+	I915_WRITE(reg, temp);
+
+	reg = FDI_RX_CTL(pipe);
+	temp = I915_READ(reg);
+	if (HAS_PCH_CPT(dev)) {
+		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
+		temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
+	} else {
+		temp &= ~FDI_LINK_TRAIN_NONE;
+		temp |= FDI_LINK_TRAIN_PATTERN_1;
+	}
+	/* BPC in FDI rx is consistent with that in PIPECONF */
+	temp &= ~(0x07 << 16);
+	temp |= (I915_READ(PIPECONF(pipe)) & PIPE_BPC_MASK) << 11;
+	I915_WRITE(reg, temp);
+
+	POSTING_READ(reg);
+	udelay(100);
+}
+
 /*
  * 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.
@@ -2691,50 +2750,7 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 	I915_WRITE(pipe ? PFB_CTL_1 : PFA_CTL_1, 0);
 	I915_WRITE(pipe ? PFB_WIN_SZ : PFA_WIN_SZ, 0);
 
-	/* disable CPU FDI tx and PCH FDI rx */
-	reg = FDI_TX_CTL(pipe);
-	temp = I915_READ(reg);
-	I915_WRITE(reg, temp & ~FDI_TX_ENABLE);
-	POSTING_READ(reg);
-
-	reg = FDI_RX_CTL(pipe);
-	temp = I915_READ(reg);
-	temp &= ~(0x7 << 16);
-	temp |= (I915_READ(PIPECONF(pipe)) & PIPE_BPC_MASK) << 11;
-	I915_WRITE(reg, temp & ~FDI_RX_ENABLE);
-
-	POSTING_READ(reg);
-	udelay(100);
-
-	/* Ironlake workaround, disable clock pointer after downing FDI */
-	if (HAS_PCH_IBX(dev))
-		I915_WRITE(FDI_RX_CHICKEN(pipe),
-			   I915_READ(FDI_RX_CHICKEN(pipe) &
-				     ~FDI_RX_PHASE_SYNC_POINTER_ENABLE));
-
-	/* still set train pattern 1 */
-	reg = FDI_TX_CTL(pipe);
-	temp = I915_READ(reg);
-	temp &= ~FDI_LINK_TRAIN_NONE;
-	temp |= FDI_LINK_TRAIN_PATTERN_1;
-	I915_WRITE(reg, temp);
-
-	reg = FDI_RX_CTL(pipe);
-	temp = I915_READ(reg);
-	if (HAS_PCH_CPT(dev)) {
-		temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
-		temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
-	} else {
-		temp &= ~FDI_LINK_TRAIN_NONE;
-		temp |= FDI_LINK_TRAIN_PATTERN_1;
-	}
-	/* BPC in FDI rx is consistent with that in PIPECONF */
-	temp &= ~(0x07 << 16);
-	temp |= (I915_READ(PIPECONF(pipe)) & PIPE_BPC_MASK) << 11;
-	I915_WRITE(reg, temp);
-
-	POSTING_READ(reg);
-	udelay(100);
+	ironlake_fdi_disable(crtc);
 
 	if (intel_pipe_has_type(crtc, INTEL_OUTPUT_LVDS)) {
 		temp = I915_READ(PCH_LVDS);