Revert "drm/i915/ringbuffer: Ignore failure to setup the ring on Sandybridge"

This reverts commit 629e8941.

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -180,21 +180,6 @@ static int init_ring_common(struct intel_ring_buffer *ring)
 	if ((I915_READ_CTL(ring) & RING_VALID) == 0 ||
 	    I915_READ_START(ring) != obj_priv->gtt_offset ||
 	    (I915_READ_HEAD(ring) & HEAD_ADDR) != 0) {
-		if (IS_GEN6(ring->dev) && ring->dev->pdev->revision <= 8) {
-			/* Early revisions of Sandybridge do not like
-			 * revealing the contents of the ring buffer
-			 * registers whilst idle. Fortunately, the
-			 * auto-reporting mechanism prevents most hangs,
-			 * but this will bite us eventually...
-			 */
-			DRM_DEBUG("%s initialization failed "
-				  "ctl %08x head %08x tail %08x start %08x. Ignoring, hope for the best!\n",
-				  ring->name,
-				  I915_READ_CTL(ring),
-				  I915_READ_HEAD(ring),
-				  I915_READ_TAIL(ring),
-				  I915_READ_START(ring));
-		} else {
 		DRM_ERROR("%s initialization failed "
 				"ctl %08x head %08x tail %08x start %08x\n",
 				ring->name,
@@ -204,7 +189,6 @@ static int init_ring_common(struct intel_ring_buffer *ring)
 				I915_READ_START(ring));
 		return -EIO;
 	}
-	}
 
 	if (!drm_core_check_feature(ring->dev, DRIVER_MODESET))
 		i915_kernel_lost_context(ring->dev);