PPARALLEL_IEEE_FWD_TO_REV callback function (parallel.h)

Article
02/22/2024

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

Syntax

PPARALLEL_IEEE_FWD_TO_REV PparallelIeeeFwdToRev;

NTSTATUS PparallelIeeeFwdToRev(
  [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 forward to reverse.
STATUS_Xxx	An internal operation resulted in an NTSTATUS error.

Remarks

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

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

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

Requirements

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

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