---
title: clearMemoryDescriptor
framework: kernel
role: pseudoSymbol
path: kernel/iodmacommand/1811032-clearmemorydescriptor
---

# clearMemoryDescriptor

Clears the DMACommand's current memory descriptor

## Declaration

```occ
virtual IOReturn clearMemoryDescriptor(
 bool autoComplete = true); 
```

## Parameters

- `autoComplete`: An optional boolean variable that will call the complete() function automatically before the memory descriptor is processed. Defaults to true.

## Overview

Overview completes and invalidates the cache if the DMA command is currently active, copies all data from bounce buffers if necessary and releases all resources acquired during setMemoryDescriptor.

## See Also

### Configuring the Memory Descriptor

- [setMemoryDescriptor](kernel/iodmacommand/1811308-setmemorydescriptor.md)
- [setMemoryDescriptor](kernel/iodmacommand/1547727-setmemorydescriptor.md)
- [clearMemoryDescriptor](kernel/iodmacommand/1547715-clearmemorydescriptor.md)
- [getMemoryDescriptor](kernel/iodmacommand/1811175-getmemorydescriptor.md)
- [getMemoryDescriptor](kernel/iodmacommand/1547753-getmemorydescriptor.md)
- [getIOMemoryDescriptor](kernel/iodmacommand/1547736-getiomemorydescriptor.md)
- [getPreparedOffsetAndLength](kernel/iodmacommand/1811194-getpreparedoffsetandlength.md)
- [getPreparedOffsetAndLength](kernel/iodmacommand/1547765-getpreparedoffsetandlength.md)
- [genIOVMSegments](kernel/iodmacommand/1811150-geniovmsegments.md)
- [genIOVMSegments](kernel/iodmacommand/1547720-geniovmsegments.md)
- [gen32IOVMSegments](kernel/iodmacommand/1811104-gen32iovmsegments.md)
- [gen32IOVMSegments](kernel/iodmacommand/1547749-gen32iovmsegments.md)
- [gen64IOVMSegments](kernel/iodmacommand/1811126-gen64iovmsegments.md)
- [gen64IOVMSegments](kernel/iodmacommand/1547722-gen64iovmsegments.md)
- [createCopyBuffer](kernel/iodmacommand/1547729-createcopybuffer.md)