diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
index 31d334d..3a3ebaf 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -107,10 +107,10 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 		 */
 		swizzle_x = I915_BIT_6_SWIZZLE_NONE;
 		swizzle_y = I915_BIT_6_SWIZZLE_NONE;
-	} else if (IS_MOBILE(dev)) {
+	} else if (!(IS_G33(dev) || IS_G4X(dev))) {
 		uint32_t dcc;
 
-		/* On mobile 9xx chipsets, channel interleave by the CPU is
+		/* On 9xx chipsets, channel interleave by the CPU is
 		 * determined by DCC.  For single-channel, neither the CPU
 		 * nor the GPU do swizzling.  For dual channel interleaved,
 		 * the GPU's interleave is bit 9 and 10 for X tiled, and bit
@@ -150,26 +150,10 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
 			swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
 		}
 	} else {
-		/* The 965, G33, and newer, have a very flexible memory
-		 * configuration.  It will enable dual-channel mode
-		 * (interleaving) on as much memory as it can, and the GPU
-		 * will additionally sometimes enable different bit 6
-		 * swizzling for tiled objects from the CPU.
-		 *
-		 * Here's what I found on the G965:
-		 *    slot fill         memory size  swizzling
-		 * 0A   0B   1A   1B    1-ch   2-ch
-		 * 512  0    0    0     512    0     O
-		 * 512  0    512  0     16     1008  X
-		 * 512  0    0    512   16     1008  X
-		 * 0    512  0    512   16     1008  X
-		 * 1024 1024 1024 0     2048   1024  O
-		 *
-		 * We could probably detect this based on either the DRB
-		 * matching, which was the case for the swizzling required in
-		 * the table above, or from the 1-ch value being less than
-		 * the minimum size of a rank.
-		 */
+		/* GPUs with VT-d support don't have bit17 swizzling anymore for
+		 * rather obvious reasons. Swizzling seems to be enabled when
+		 * both channels have the same configuration, no cpu (bit11)
+		 * swizzling happens in addition. */
 		if (I915_READ16(C0DRB3) != I915_READ16(C1DRB3)) {
 			swizzle_x = I915_BIT_6_SWIZZLE_NONE;
 			swizzle_y = I915_BIT_6_SWIZZLE_NONE;