AVC_FUNCTION_GET_EXT_PLUG_COUNTS
The AVC_FUNCTION_GET_EXT_PLUG_COUNTS function code obtains the external input and output plug counts.
I/O Status Block
If successful, the AV/C protocol driver sets Irp->IoStatus.Status to STATUS_SUCCESS.
Possible other return values include:
| Return value | Description |
|---|---|
| STATUS_TIMEOUT | The request was made, but no response was received before all time-out and retry processing was complete. |
| STATUS_REQUEST_ABORTED | Immediately abort when the IRP completion status is STATUS_REQUEST_ABORTED. This indicates that the device has been removed or is no longer available on the 1394 bus. |
| STATUS_* | Any other return code indicates that an error or warning occurred that was beyond the scope of the AV/C protocol. |
Comments
This function uses the ExtPlugCounts member of the AVC_MULTIFUNC_IRB structure as shown below.
typedef struct _AVC_MULTIFUNC_IRB {
AVC_IRB Common;
union {
.
.
.
AVC_EXT_PLUG_COUNTS ExtPlugCounts;
.
.
.
};
} AVC_MULTIFUNC_IRB, *PAVC_MULTIFUNC_IRB;
Requirements
Headers: Declared in avc.h. Include avc.h.
AVC_MULTIFUNC_IRB Input
Common
The Function submember of this member must be set to AVC_FUNCTION_GET_EXT_PLUG_COUNTS from the AVC_FUNCTION enumeration.
ExtPlugCounts
Specifies the count of external input and output plugs.
This function code is not supported by virtual instances of avc.sys.
Subunit drivers are responsible for determining the function, format, and use of external plugs. Avc.sys does, however, report any permanent connections between external plugs and subunit plugs as dedicated pins on the subunit (for more information, see AVC_FUNCTION_GET_CONNECTINFO).
This must be called at IRQL = PASSIVE_LEVEL.