Stream Class SRB Reference
The class driver uses the HW_STREAM_REQUEST_BLOCK structure to pass SRB requests to the minidriver. In this reference section, pSRB refers to a pointer to a HW_STREAM_REQUEST_BLOCK object. The stream class driver passes this pointer when it calls minidriver-provided callbacks.
SRB requests are either device/instance-specific or stream-specific. Depending on the SRB command, additional parameters may be passed in the HW_STREAM_REQUEST_BLOCK.