REQUEST_ISOCH_FREE_BANDWIDTH control code

The REQUEST_ISOCH_FREE_BANDWIDTH request releases isochronous bandwidth that was allocated through a REQUEST_ISOCH_ALLOCATE_BANDWIDTH request.

The relevant members of the IRB for this request are:


typedef struct _IRB {
  ULONG FunctionNumber;
    .
    .
    .
  union {
    struct {
      HANDLE    hBandwidth; 
    } IsochFreeBandwidth;
    .
    .
    .
  } u;
} IRB;

IRB Input

FunctionNumber

REQUEST_ISOCH_FREE_BANDWIDTH

u.IsochFreeBandwidth.hBandwidth

Specifies the bandwidth handle to release.

I/O Status Block

If successful, the bus driver sets Irp->IoStatus.Status to STATUS_SUCCESS, and the isochronous bandwidth is returned to the pool of available bandwidth.

A status of STATUS_INVALID_GENERATION also indicates success.

Do not resend the REQUEST_ISOCH_FREE_BANDWIDTH request in order to release isochronous bandwidth if the request failed with the STATUS_INVALID_GENERATION error code. In that case, it is safe to assume that isochronous bandwidth was released as a result of 1394 bus generation changes.

See Also

IOCTL_IEEE1394_API_REQUEST

Requirements

Header

1394.h (include 1394.h)

IRQL

PASSIVE_LEVEL

 

 

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