PPARALLEL_IEEE_REV_TO_FWD callback function (parallel.h)

Article
02/22/2024

The PPARALLEL_IEEE_REV_TO_FWD-typed callback routine changes the transfer mode from reverse to forward. The system-supplied bus driver for parallel ports supplies this routine.

Syntax

PPARALLEL_IEEE_REV_TO_FWD PparallelIeeeRevToFwd;

NTSTATUS PparallelIeeeRevToFwd(
  [in] PVOID Context
)
{...}

Parameters

[in] Context

Pointer to a device extension of a parallel device's physical device object (PDO).

Return value

Return code	Description
STATUS_SUCCESS	The transfer mode was changed from reverse to forward.
STATUS_Xxx	An internal operation resulted in an NTSTATUS error.

Remarks

To obtain a pointer to the system-supplied PPARALLEL_IEEE_REV_TO_FWD callback, a kernel-mode driver uses an IOCTL_INTERNAL_PARCLASS_CONNECT request, which returns a PARCLASS_INFORMATION structure. The IeeeRevToFwdMode member of the PARCLASS_INFORMATION structure is a pointer to this callback.

If the device is connected and is in the forward mode, the PPARALLEL_IEEE_REV_TO_FWD callback returns without further processing. Otherwise, the PPARALLEL_IEEE_REV_TO_FWD callback puts a parallel device in the forward mode and connects a previously negotiated forward protocol. The PNEGOTIATE_IEEE_MODE callback can be used to negotiate a forward protocol.

The PPARALLEL_IEEE_REV_TO_FWD callback runs in the caller's thread at the IRQL of the caller.

Requirements

Requirement	Value
Target Platform	Desktop
Header	parallel.h (include Parallel.h)

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