---
title: readDiscInfo
framework: kernel
role: pseudoSymbol
path: kernel/iobdmedia/1811707-readdiscinfo
---

# readDiscInfo

## Declaration

```occ
virtual IOReturn readDiscInfo(
 IOMemoryDescriptor *buffer, 
 UInt8type, 
 UInt16 *actualByteCount ); 
```

## Parameters

- `buffer`: Buffer for the data transfer. The size of the buffer implies the size of the data transfer.
- `type`: Reserved for future use. Set to zero.
- `actualByteCount`: Returns the actual number of bytes transferred in the data transfer.

## Return Value

Return Value Returns the status of the data transfer.

## Overview

Overview Issue an MMC READ DISC INFORMATION command.

## See Also

### Miscellaneous

- [getSpeed](kernel/iobdmedia/1811688-getspeed.md)
- [readStructure](kernel/iobdmedia/1811722-readstructure.md)
- [readTrackInfo](kernel/iobdmedia/1811739-readtrackinfo.md)
- [reportKey](kernel/iobdmedia/1811756-reportkey.md)
- [sendKey](kernel/iobdmedia/1811776-sendkey.md)
- [setSpeed](kernel/iobdmedia/1811802-setspeed.md)
- [splitTrack](kernel/iobdmedia/1811824-splittrack.md)