diff --git a/drivers/iio/adc/mcp3422.c b/drivers/iio/adc/mcp3422.c
index 219adac2384b..da353dcb1e9d 100644
--- a/drivers/iio/adc/mcp3422.c
+++ b/drivers/iio/adc/mcp3422.c
@@ -143,8 +143,10 @@ static int mcp3422_read_channel(struct mcp3422 *adc,
 		config &= ~MCP3422_PGA_MASK;
 		config |= MCP3422_PGA_VALUE(adc->pga[req_channel]);
 		ret = mcp3422_update_config(adc, config);
-		if (ret < 0)
+		if (ret < 0) {
+			mutex_unlock(&adc->lock);
 			return ret;
+		}
 		msleep(mcp3422_read_times[MCP3422_SAMPLE_RATE(adc->config)]);
 	}