diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 637c13211613bc9413fa4e65b34fd0728669218d..e6b406e4565bf1b0ed66804be7ff1ac66c9878fe 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -139,27 +139,30 @@ static const u32 hpd_bxt[HPD_NUM_PINS] = {
 /*
  * We should clear IMR at preinstall/uninstall, and just check at postinstall.
  */
-#define GEN5_ASSERT_IIR_IS_ZERO(reg) do { \
-	u32 val = I915_READ(reg); \
-	if (val) { \
-		WARN(1, "Interrupt register 0x%x is not zero: 0x%08x\n", \
-		     (reg), val); \
-		I915_WRITE((reg), 0xffffffff); \
-		POSTING_READ(reg); \
-		I915_WRITE((reg), 0xffffffff); \
-		POSTING_READ(reg); \
-	} \
-} while (0)
+static void gen5_assert_iir_is_zero(struct drm_i915_private *dev_priv, u32 reg)
+{
+	u32 val = I915_READ(reg);
+
+	if (val == 0)
+		return;
+
+	WARN(1, "Interrupt register 0x%x is not zero: 0x%08x\n",
+	     reg, val);
+	I915_WRITE(reg, 0xffffffff);
+	POSTING_READ(reg);
+	I915_WRITE(reg, 0xffffffff);
+	POSTING_READ(reg);
+}
 
 #define GEN8_IRQ_INIT_NDX(type, which, imr_val, ier_val) do { \
-	GEN5_ASSERT_IIR_IS_ZERO(GEN8_##type##_IIR(which)); \
+	gen5_assert_iir_is_zero(dev_priv, GEN8_##type##_IIR(which)); \
 	I915_WRITE(GEN8_##type##_IER(which), (ier_val)); \
 	I915_WRITE(GEN8_##type##_IMR(which), (imr_val)); \
 	POSTING_READ(GEN8_##type##_IMR(which)); \
 } while (0)
 
 #define GEN5_IRQ_INIT(type, imr_val, ier_val) do { \
-	GEN5_ASSERT_IIR_IS_ZERO(type##IIR); \
+	gen5_assert_iir_is_zero(dev_priv, type##IIR); \
 	I915_WRITE(type##IER, (ier_val)); \
 	I915_WRITE(type##IMR, (imr_val)); \
 	POSTING_READ(type##IMR); \
@@ -3365,7 +3368,7 @@ static void ibx_irq_postinstall(struct drm_device *dev)
 	else
 		mask = SDE_GMBUS_CPT | SDE_AUX_MASK_CPT;
 
-	GEN5_ASSERT_IIR_IS_ZERO(SDEIIR);
+	gen5_assert_iir_is_zero(dev_priv, SDEIIR);
 	I915_WRITE(SDEIMR, ~mask);
 }