diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 58e6676..35d2ace 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1553,7 +1553,7 @@ static int i915_dpio_info(struct seq_file *m, void *data)
 		return 0;
 	}
 
-	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
+	ret = mutex_lock_interruptible(&dev_priv->dpio_lock);
 	if (ret)
 		return ret;
 
@@ -1582,7 +1582,7 @@ static int i915_dpio_info(struct seq_file *m, void *data)
 	seq_printf(m, "DPIO_FASTCLK_DISABLE: 0x%08x\n",
 		   intel_dpio_read(dev_priv, DPIO_FASTCLK_DISABLE));
 
-	mutex_unlock(&dev->mode_config.mutex);
+	mutex_unlock(&dev_priv->dpio_lock);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 2635ee6..ad488f6 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1579,7 +1579,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	spin_lock_init(&dev_priv->irq_lock);
 	spin_lock_init(&dev_priv->error_lock);
 	spin_lock_init(&dev_priv->rps.lock);
-	spin_lock_init(&dev_priv->dpio_lock);
+	mutex_init(&dev_priv->dpio_lock);
 
 	mutex_init(&dev_priv->rps.hw_lock);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e2944e9..6fa0c00 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -655,7 +655,7 @@ typedef struct drm_i915_private {
 	spinlock_t irq_lock;
 
 	/* DPIO indirect register protection */
-	spinlock_t dpio_lock;
+	struct mutex dpio_lock;
 
 	/** Cached value of IMR to avoid reads in updating the bitfield */
 	u32 pipestat[2];
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d303f2a..a0d8869 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -416,13 +416,11 @@ static const intel_limit_t intel_limits_vlv_dp = {
 
 u32 intel_dpio_read(struct drm_i915_private *dev_priv, int reg)
 {
-	unsigned long flags;
-	u32 val = 0;
+	WARN_ON(!mutex_is_locked(&dev_priv->dpio_lock));
 
-	spin_lock_irqsave(&dev_priv->dpio_lock, flags);
 	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100)) {
 		DRM_ERROR("DPIO idle wait timed out\n");
-		goto out_unlock;
+		return 0;
 	}
 
 	I915_WRITE(DPIO_REG, reg);
@@ -430,24 +428,20 @@ u32 intel_dpio_read(struct drm_i915_private *dev_priv, int reg)
 		   DPIO_BYTE);
 	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100)) {
 		DRM_ERROR("DPIO read wait timed out\n");
-		goto out_unlock;
+		return 0;
 	}
-	val = I915_READ(DPIO_DATA);
 
-out_unlock:
-	spin_unlock_irqrestore(&dev_priv->dpio_lock, flags);
-	return val;
+	return I915_READ(DPIO_DATA);
 }
 
 static void intel_dpio_write(struct drm_i915_private *dev_priv, int reg,
 			     u32 val)
 {
-	unsigned long flags;
+	WARN_ON(!mutex_is_locked(&dev_priv->dpio_lock));
 
-	spin_lock_irqsave(&dev_priv->dpio_lock, flags);
 	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100)) {
 		DRM_ERROR("DPIO idle wait timed out\n");
-		goto out_unlock;
+		return;
 	}
 
 	I915_WRITE(DPIO_DATA, val);
@@ -456,9 +450,6 @@ static void intel_dpio_write(struct drm_i915_private *dev_priv, int reg,
 		   DPIO_BYTE);
 	if (wait_for_atomic_us((I915_READ(DPIO_PKT) & DPIO_BUSY) == 0, 100))
 		DRM_ERROR("DPIO write wait timed out\n");
-
-out_unlock:
-       spin_unlock_irqrestore(&dev_priv->dpio_lock, flags);
 }
 
 static void vlv_init_dpio(struct drm_device *dev)
@@ -1455,13 +1446,12 @@ static void intel_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 static void
 intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value)
 {
-	unsigned long flags;
+	WARN_ON(!mutex_is_locked(&dev_priv->dpio_lock));
 
-	spin_lock_irqsave(&dev_priv->dpio_lock, flags);
 	if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_BUSY) == 0,
 				100)) {
 		DRM_ERROR("timeout waiting for SBI to become ready\n");
-		goto out_unlock;
+		return;
 	}
 
 	I915_WRITE(SBI_ADDR,
@@ -1475,24 +1465,19 @@ intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value)
 	if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_BUSY | SBI_RESPONSE_FAIL)) == 0,
 				100)) {
 		DRM_ERROR("timeout waiting for SBI to complete write transaction\n");
-		goto out_unlock;
+		return;
 	}
-
-out_unlock:
-	spin_unlock_irqrestore(&dev_priv->dpio_lock, flags);
 }
 
 static u32
 intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg)
 {
-	unsigned long flags;
-	u32 value = 0;
+	WARN_ON(!mutex_is_locked(&dev_priv->dpio_lock));
 
-	spin_lock_irqsave(&dev_priv->dpio_lock, flags);
 	if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_BUSY) == 0,
 				100)) {
 		DRM_ERROR("timeout waiting for SBI to become ready\n");
-		goto out_unlock;
+		return 0;
 	}
 
 	I915_WRITE(SBI_ADDR,
@@ -1504,14 +1489,10 @@ intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg)
 	if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_BUSY | SBI_RESPONSE_FAIL)) == 0,
 				100)) {
 		DRM_ERROR("timeout waiting for SBI to complete read transaction\n");
-		goto out_unlock;
+		return 0;
 	}
 
-	value = I915_READ(SBI_DATA);
-
-out_unlock:
-	spin_unlock_irqrestore(&dev_priv->dpio_lock, flags);
-	return value;
+	return I915_READ(SBI_DATA);
 }
 
 /**
@@ -2960,6 +2941,8 @@ static void lpt_program_iclkip(struct drm_crtc *crtc)
 	u32 divsel, phaseinc, auxdiv, phasedir = 0;
 	u32 temp;
 
+	mutex_lock(&dev_priv->dpio_lock);
+
 	/* It is necessary to ungate the pixclk gate prior to programming
 	 * the divisors, and gate it back when it is done.
 	 */
@@ -3041,6 +3024,8 @@ static void lpt_program_iclkip(struct drm_crtc *crtc)
 	udelay(24);
 
 	I915_WRITE(PIXCLK_GATE, PIXCLK_GATE_UNGATE);
+
+	mutex_unlock(&dev_priv->dpio_lock);
 }
 
 /*
@@ -4268,6 +4253,8 @@ static void vlv_update_pll(struct drm_crtc *crtc,
 	bool is_sdvo;
 	u32 temp;
 
+	mutex_lock(&dev_priv->dpio_lock);
+
 	is_sdvo = intel_pipe_has_type(crtc, INTEL_OUTPUT_SDVO) ||
 		intel_pipe_has_type(crtc, INTEL_OUTPUT_HDMI);
 
@@ -4351,6 +4338,8 @@ static void vlv_update_pll(struct drm_crtc *crtc,
 			temp |= (1 << 21);
 		intel_dpio_write(dev_priv, DPIO_DATA_CHANNEL2, temp);
 	}
+
+	mutex_unlock(&dev_priv->dpio_lock);
 }
 
 static void i9xx_update_pll(struct drm_crtc *crtc,
