PFNUSBCAMD_BulkReadWrite callback function (usbcamdi.h)

Article
03/13/2023

The USBCAMD_BulkReadWrite service performs a read or write operation on the specified bulk pipe.

Syntax

PFNUSBCAMD_BulkReadWrite PfnusbcamdBulkreadwrite;

NTSTATUS PfnusbcamdBulkreadwrite(
  [in] PVOID DeviceContext,
  [in] USHORT PipeIndex,
  [in] PVOID Buffer,
  [in] ULONG BufferLength,
  [in] PCOMMAND_COMPLETE_FUNCTION CommandComplete,
  [in] PVOID CommandContext
)
{...}

Parameters

[in] DeviceContext

Pointer to the camera minidriver's device context.

[in] PipeIndex

Specifies the index of the bulk pipe.

[in] Buffer

Pointer to the read or write buffer. If this parameter is set to NULL for a read request, USBCAMD pulls a data SRB from the SRB read queue of the stream associated with this pipe. Write requests with a NULL buffer pointer are only permitted on the still pin if an SRB_WRITE_DATA request has been submitted to the still pin.

[in] BufferLength

Specifies the length of the read/write buffer in bytes.

[in] CommandComplete

Pointer to a camera minidriver defined CommandCompleteFunction, which is called when the bulk read or write is completed. This value can be NULL.

[in] CommandContext

Pointer to a block of memory, that is passed as an argument to the camera minidriver defined CommandCompleteFunction.

Return value

USBCAMD_BulkReadWrite returns STATUS_SUCCESS if the call was successful. Other possible error codes include:

Return code	Description
STATUS_FILE_CLOSED	The device has been removed.
STATUS_INVALID_PARAMETER	USBCAMD may return STATUS_INVALID_PARAMETER for a number of reasons, including: The value passed in the PipeIndex argument is invalid. The type of the pipe specified by the PipeIndex argument represents an invalid type of pipe. A bulk read/write request already exists. The Buffer argument is NULL.
STATUS_INSUFFICIENT_RESOURCES	There are insufficient resources to schedule a transfer.

Remarks

USBCAMD can accept one read and one write request at a time.

USBCAMD_BulkReadWrite is not available in USBCAMD version 1.0.

Requirements

Requirement	Value
Target Platform	Desktop
Header	usbcamdi.h (include Usbcamdi.h)