drm/i915: Fix up the bdw pipe interrupt enable lists

- Pipe underrun can't just be enabled, we need some support code like
  on ilk-hsw to make this happen. So drop it for now.
- CRC error is a special mode of the CRC hardware that we don't use,
  so again drop it. Real CRC support for bdw will be added later.
- All the other error bits are about faults, so rename the #define and
  adjust the output.

v2: Use pipe_name as pointed out by Ville. Ville's comment was on a
previous patch, but it was easier to squash in here.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -1793,8 +1793,11 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
 			intel_finish_page_flip_plane(dev, pipe);
 		}
 
-		if (pipe_iir & GEN8_DE_PIPE_IRQ_ERRORS)
-			DRM_ERROR("Errors on pipe %c\n", 'A' + pipe);
+		if (pipe_iir & GEN8_DE_PIPE_IRQ_FAULT_ERRORS) {
+			DRM_ERROR("Fault errors on pipe %c\n: 0x%08x",
+				  pipe_name(pipe),
+				  pipe_iir & GEN8_DE_PIPE_IRQ_FAULT_ERRORS);
+		}
 
 		if (pipe_iir) {
 			ret = IRQ_HANDLED;
@@ -2863,9 +2866,8 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *dev = dev_priv->dev;
 	uint32_t de_pipe_enables = GEN8_PIPE_FLIP_DONE |
-				   GEN8_PIPE_SCAN_LINE_EVENT |
 				   GEN8_PIPE_VBLANK |
-				   GEN8_DE_PIPE_IRQ_ERRORS;
+				   GEN8_DE_PIPE_IRQ_FAULT_ERRORS;
 	int pipe;
 	dev_priv->de_irq_mask[PIPE_A] = ~de_pipe_enables;
 	dev_priv->de_irq_mask[PIPE_B] = ~de_pipe_enables;

drivers/gpu/drm/i915/i915_reg.h

@@ -4064,9 +4064,8 @@
 #define  GEN8_PIPE_SCAN_LINE_EVENT	(1 << 2)
 #define  GEN8_PIPE_VSYNC		(1 << 1)
 #define  GEN8_PIPE_VBLANK		(1 << 0)
-#define GEN8_DE_PIPE_IRQ_ERRORS	(GEN8_PIPE_UNDERRUN | \
-				 GEN8_PIPE_CDCLK_CRC_ERROR | \
-				 GEN8_PIPE_CURSOR_FAULT | \
+#define GEN8_DE_PIPE_IRQ_FAULT_ERRORS \
+	(GEN8_PIPE_CURSOR_FAULT | \
 	 GEN8_PIPE_SPRITE_FAULT | \
 	 GEN8_PIPE_PRIMARY_FAULT)