diff --git a/shared-core/radeon_irq.c b/shared-core/radeon_irq.c
index 69569961..836f384d 100644
--- a/shared-core/radeon_irq.c
+++ b/shared-core/radeon_irq.c
@@ -44,7 +44,8 @@ void radeon_irq_set_state(struct drm_device *dev, u32 mask, int state)
 	else
 		dev_priv->irq_enable_reg &= ~mask;
 
-	RADEON_WRITE(RADEON_GEN_INT_CNTL, dev_priv->irq_enable_reg);
+	if (dev->irq_enabled)
+		RADEON_WRITE(RADEON_GEN_INT_CNTL, dev_priv->irq_enable_reg);
 }
 
 static void r500_vbl_irq_set_state(struct drm_device *dev, u32 mask, int state)
@@ -56,7 +57,8 @@ static void r500_vbl_irq_set_state(struct drm_device *dev, u32 mask, int state)
 	else
 		dev_priv->r500_disp_irq_reg &= ~mask;
 
-	RADEON_WRITE(R500_DxMODE_INT_MASK, dev_priv->r500_disp_irq_reg);
+	if (dev->irq_enabled)
+		RADEON_WRITE(R500_DxMODE_INT_MASK, dev_priv->r500_disp_irq_reg);
 }
 
 int radeon_enable_vblank(struct drm_device *dev, int crtc)