Lucent Technologies USS-720 manual Ioctlgetconfigurationdescriptor, 4 I/O Control Codes continued

USS-720	Preliminary User Guide, Rev. 2
USB Device Driver	February 1999

4 I/O Control Codes (continued)

4.11 IOCTL_GET_CONFIGURATION_DESCRIPTOR

IOCTL_GET_CONFIGURATION_DESCRIPTOR retrieves the current configuration descriptor. Details regarding parameters and error codes follow.

4.11.1 Parameters

lpInBuffer—Points to an input buffer. Not used with this operation. Set to NULL.

nInBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpInBuffer. Not used with this operation. Set to zero.

lpOutBuffer—Points to an output buffer that will receive a USB_CONFIGURATION_DESCRIPTOR data structure (see WDM USB Driver Specification).

nOutBufferSize—Specifies the size (in bytes) of the buffer pointed to by lpOutBuffer, which must be large enough to contain the USB_CONFIGURATION_DESCRIPTOR data structure (see WDM USB Driver Specification). Specify zero to return only the length of the Device ID string in lpBytesReturned.

lpBytesReturned—Points to a DWORD that receives the actual size (in bytes) of the data stored into lpOutBuffer.

4.11.2 Notes

None.

4.11.3 Error Code

ERROR_NOT_ENOUGH_BUFFER—lpOutBuffer was not large enough to receive the USB Configuration Descriptor.

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