diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index d4adf28..7419fbf 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7123,6 +7123,15 @@
 
 #define GEN6_PCODE_MAILBOX			_MMIO(0x138124)
 #define   GEN6_PCODE_READY			(1<<31)
+#define   GEN6_PCODE_ERROR_MASK			0xFF
+#define     GEN6_PCODE_SUCCESS			0x0
+#define     GEN6_PCODE_ILLEGAL_CMD		0x1
+#define     GEN6_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE 0x2
+#define     GEN6_PCODE_TIMEOUT			0x3
+#define     GEN6_PCODE_UNIMPLEMENTED_CMD	0xFF
+#define     GEN7_PCODE_TIMEOUT			0x2
+#define     GEN7_PCODE_ILLEGAL_DATA		0x3
+#define     GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE 0x10
 #define	  GEN6_PCODE_WRITE_RC6VIDS		0x4
 #define	  GEN6_PCODE_READ_RC6VIDS		0x5
 #define     GEN6_ENCODE_RC6_VID(mv)		(((mv) - 245) / 5)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8a6751e..d0b7455 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -7659,8 +7659,53 @@
 	}
 }
 
+static inline int gen6_check_mailbox_status(struct drm_i915_private *dev_priv)
+{
+	uint32_t flags =
+		I915_READ_FW(GEN6_PCODE_MAILBOX) & GEN6_PCODE_ERROR_MASK;
+
+	switch (flags) {
+	case GEN6_PCODE_SUCCESS:
+		return 0;
+	case GEN6_PCODE_UNIMPLEMENTED_CMD:
+	case GEN6_PCODE_ILLEGAL_CMD:
+		return -ENXIO;
+	case GEN6_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
+		return -EOVERFLOW;
+	case GEN6_PCODE_TIMEOUT:
+		return -ETIMEDOUT;
+	default:
+		MISSING_CASE(flags)
+		return 0;
+	}
+}
+
+static inline int gen7_check_mailbox_status(struct drm_i915_private *dev_priv)
+{
+	uint32_t flags =
+		I915_READ_FW(GEN6_PCODE_MAILBOX) & GEN6_PCODE_ERROR_MASK;
+
+	switch (flags) {
+	case GEN6_PCODE_SUCCESS:
+		return 0;
+	case GEN6_PCODE_ILLEGAL_CMD:
+		return -ENXIO;
+	case GEN7_PCODE_TIMEOUT:
+		return -ETIMEDOUT;
+	case GEN7_PCODE_ILLEGAL_DATA:
+		return -EINVAL;
+	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
+		return -EOVERFLOW;
+	default:
+		MISSING_CASE(flags);
+		return 0;
+	}
+}
+
 int sandybridge_pcode_read(struct drm_i915_private *dev_priv, u32 mbox, u32 *val)
 {
+	int status;
+
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
 	/* GEN6_PCODE_* are outside of the forcewake domain, we can
@@ -7687,12 +7732,25 @@
 	*val = I915_READ_FW(GEN6_PCODE_DATA);
 	I915_WRITE_FW(GEN6_PCODE_DATA, 0);
 
+	if (INTEL_GEN(dev_priv) > 6)
+		status = gen7_check_mailbox_status(dev_priv);
+	else
+		status = gen6_check_mailbox_status(dev_priv);
+
+	if (status) {
+		DRM_DEBUG_DRIVER("warning: pcode (read) mailbox access failed: %d\n",
+				 status);
+		return status;
+	}
+
 	return 0;
 }
 
 int sandybridge_pcode_write(struct drm_i915_private *dev_priv,
-			       u32 mbox, u32 val)
+			    u32 mbox, u32 val)
 {
+	int status;
+
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
 	/* GEN6_PCODE_* are outside of the forcewake domain, we can
@@ -7717,6 +7775,17 @@
 
 	I915_WRITE_FW(GEN6_PCODE_DATA, 0);
 
+	if (INTEL_GEN(dev_priv) > 6)
+		status = gen7_check_mailbox_status(dev_priv);
+	else
+		status = gen6_check_mailbox_status(dev_priv);
+
+	if (status) {
+		DRM_DEBUG_DRIVER("warning: pcode (write) mailbox access failed: %d\n",
+				 status);
+		return status;
+	}
+
 	return 0;
 }