IO_SCSI_CAPABILITIES structure (ntddscsi.h)

The IO_SCSI_CAPABILITIES structure is used in conjunction with the IOCTL_SCSI_GET_CAPABILITIES request to retrieve the capabilities and limitations of the underlying SCSI host adapter.

Note  The SCSI port driver and SCSI miniport driver models may be altered or unavailable in the future. Instead, we recommend using the Storport driver and Storport miniport driver models.

 

Syntax

typedef struct _IO_SCSI_CAPABILITIES {
  ULONG   Length;
  ULONG   MaximumTransferLength;
  ULONG   MaximumPhysicalPages;
  ULONG   SupportedAsynchronousEvents;
  ULONG   AlignmentMask;
  BOOLEAN TaggedQueuing;
  BOOLEAN AdapterScansDown;
  BOOLEAN AdapterUsesPio;
} IO_SCSI_CAPABILITIES, *PIO_SCSI_CAPABILITIES;

Members

Length

Contains the length in bytes of this structure.

MaximumTransferLength

Contains the maximum size, in bytes, of a single SCSI request block (SRB).

MaximumPhysicalPages

Contains the maximum number of physical pages per data buffer.

SupportedAsynchronousEvents

When TRUE, indicates that the host adapter supports SCSI asynchronous receive-event operations.

AlignmentMask

Contains the alignment mask for data transfers. The host adapter requires that data to be transferred must be aligned on an address that is an integer multiple of the value in this field.

TaggedQueuing

When TRUE, indicates that the host adapter supports tagged queuing.

AdapterScansDown

When TRUE, indicates that the host adapter scans down for BIOS devices.

AdapterUsesPio

When TRUE, indicates that the host adapter uses programmed I/O.

Requirements

Requirement	Value
Header	ntddscsi.h (include Ntddscsi.h)

See also

IOCTL_SCSI_GET_CAPABILITIES