1 files changed, 19 insertions, 3 deletions

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index aa13708c2bc3..d22cfae1b019 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -1274,18 +1274,26 @@ static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter,
 					     struct counter_signal *signal,
 					     void *private, char *buf)
 {
-	const struct quad8_iio *const priv = counter->priv;
+	struct quad8_iio *const priv = counter->priv;
 	const size_t channel_id = signal->id / 2;
-	const bool disabled = !(priv->cable_fault_enable & BIT(channel_id));
+	bool disabled;
 	unsigned int status;
 	unsigned int fault;
 
-	if (disabled)
+	mutex_lock(&priv->lock);
+
+	disabled = !(priv->cable_fault_enable & BIT(channel_id));
+
+	if (disabled) {
+		mutex_unlock(&priv->lock);
 		return -EINVAL;
+	}
 
 	/* Logic 0 = cable fault */
 	status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
 
+	mutex_unlock(&priv->lock);
+
 	/* Mask respective channel and invert logic */
 	fault = !(status & BIT(channel_id));
 
@@ -1317,6 +1325,8 @@ static ssize_t quad8_signal_cable_fault_enable_write(
 	if (ret)
 		return ret;
 
+	mutex_lock(&priv->lock);
+
 	if (enable)
 		priv->cable_fault_enable |= BIT(channel_id);
 	else
@@ -1327,6 +1337,8 @@ static ssize_t quad8_signal_cable_fault_enable_write(
 
 	outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
 
+	mutex_unlock(&priv->lock);
+
 	return len;
 }
 
@@ -1353,6 +1365,8 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
 	if (ret)
 		return ret;
 
+	mutex_lock(&priv->lock);
+
 	priv->fck_prescaler[channel_id] = prescaler;
 
 	/* Reset Byte Pointer */
@@ -1363,6 +1377,8 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
 	     base_offset + 1);
 
+	mutex_unlock(&priv->lock);
+
 	return len;
 }