IOCTL_WINUSB_MAP_ISOCH_WRITE_BUFFER control code

[This documentation is preliminary and is subject to change.]

The IOCTL_WINUSB_MAP_ISOCH_WRITE_BUFFER I/O control request maps, probes, and locks a user-mode output buffer and associates it with an isochronous OUT endpoint. Remains pending until cancelled.

To perform this operation, call the DeviceIoControl function with the following parameters.

Input Parameters

AssociatedIrp.SystemBuffer points to a WINUSB_ISOCH_BUFFER_DESCRIPTOR structure that contains the user-mode buffer address and its size.

Irp->MdlAddress points to a MDL that describes that buffer.

Parameters.DeviceIoControl.OutputBufferLength member indicates the size of the buffer described by Irp->MdlAddress.

Output Parameters

None.

I/O Status Block

The USB stack sets Irp->IoStatus.Status to STATUS_SUCCESS if the request is successful. Otherwise, the USB driver stack sets Status to the appropriate error condition, such as STATUS_INVALID_PARAMETER or STATUS_INSUFFICIENT_RESOURCES.

Remarks

An IOCTL_WINUSB_MAP_ISOCH_WRITE_BUFFER request remains pending until it is canceled. When it is canceled, the user-mode buffer is unlocked. Uses METHOD_OUT_DIRECT.

Requirements

Header

WinIoctl.h

See also

DeviceIoControl

 

 

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Build date: 6/19/2013

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