diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 165a38f36009..479e0c119111 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2347,7 +2347,7 @@ static const char *power_domain_str(enum intel_display_power_domain domain)
 	case POWER_DOMAIN_INIT:
 		return "INIT";
 	default:
-		WARN_ON(1);
+		MISSING_CASE(domain);
 		return "?";
 	}
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c74dc946cbf6..5f4cca3ef01c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -58,7 +58,19 @@
 #define DRIVER_DATE		"20141205"
 
 #undef WARN_ON
-#define WARN_ON(x)		WARN(x, "WARN_ON(" #x ")")
+/* Many gcc seem to no see through this and fall over :( */
+#if 0
+#define WARN_ON(x) ({ \
+	bool __i915_warn_cond = (x); \
+	if (__builtin_constant_p(__i915_warn_cond)) \
+		BUILD_BUG_ON(__i915_warn_cond); \
+	WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
+#else
+#define WARN_ON(x) WARN((x), "WARN_ON(" #x ")")
+#endif
+
+#define MISSING_CASE(x) WARN(1, "Missing switch case (%lu) in %s\n", \
+			     (long) (x), __func__);
 
 enum pipe {
 	INVALID_PIPE = -1,
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index ac03a382000b..ce4e46c443a1 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -132,7 +132,7 @@ static gen6_gtt_pte_t snb_pte_encode(dma_addr_t addr,
 		pte |= GEN6_PTE_UNCACHED;
 		break;
 	default:
-		WARN_ON(1);
+		MISSING_CASE(level);
 	}
 
 	return pte;
@@ -156,7 +156,7 @@ static gen6_gtt_pte_t ivb_pte_encode(dma_addr_t addr,
 		pte |= GEN6_PTE_UNCACHED;
 		break;
 	default:
-		WARN_ON(1);
+		MISSING_CASE(level);
 	}
 
 	return pte;
@@ -1146,7 +1146,7 @@ int i915_ppgtt_init_hw(struct drm_device *dev)
 	else if (INTEL_INFO(dev)->gen >= 8)
 		gen8_ppgtt_enable(dev);
 	else
-		WARN_ON(1);
+		MISSING_CASE(INTEL_INFO(dev)->gen);
 
 	if (ppgtt) {
 		for_each_ring(ring, dev_priv, i) {
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 841af6c1f50b..878c4857ff49 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4847,7 +4847,7 @@ static void cherryview_set_cdclk(struct drm_device *dev, int cdclk)
 		cmd = 0;
 		break;
 	default:
-		WARN_ON(1);
+		MISSING_CASE(cdclk);
 		return;
 	}
 
@@ -8224,7 +8224,7 @@ static void i9xx_update_cursor(struct drm_crtc *crtc, u32 base)
 				cntl |= CURSOR_MODE_256_ARGB_AX;
 				break;
 			default:
-				WARN_ON(1);
+				MISSING_CASE(intel_crtc->cursor_width);
 				return;
 		}
 		cntl |= pipe << 28; /* Connect to correct pipe */
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 46de8d75b4bf..883d2febb705 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1202,7 +1202,7 @@ void intel_uncore_init(struct drm_device *dev)
 
 	switch (INTEL_INFO(dev)->gen) {
 	default:
-		WARN_ON(1);
+		MISSING_CASE(INTEL_INFO(dev)->gen);
 		return;
 	case 9:
 		ASSIGN_WRITE_MMIO_VFUNCS(gen9);
@@ -1300,7 +1300,7 @@ int i915_reg_read_ioctl(struct drm_device *dev,
 		reg->val = I915_READ8(reg->offset);
 		break;
 	default:
-		WARN_ON(1);
+		MISSING_CASE(entry->size);
 		ret = -EINVAL;
 		goto out;
 	}