After successfully registering a custom device interface in an MSVAD
based device driver, I tried using SetupDiEnumDeviceInterfaces() in a
user mode application to verify that I understood the concept.
In the user mode test program I wrote:
====================================
// Get handle to relevant device information set
HDEVINFO info = SetupDiGetClassDevs(
pGuid,
NULL,
NULL,
DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);
if (info == INVALID_HANDLE_VALUE)
{
printf("No HDEVINFO available for this GUID\n");
return NULL;
}
// Get interface data for the requested instance
SP_INTERFACE_DEVICE_DATA ifdata;
ifdata.cbSize = sizeof(ifdata);
if (!SetupDiEnumDeviceInterfaces(
info, // HDEVINFO DeviceInfoSet
NULL, // PSP_DEVINFO_DATA DeviceInfoData
pGuid, // CONST GUID * InterfaceClassGuid
instance, // DWORD MemberIndex
&ifdata)) // PSP_DEVICE_INTERFACE_DATA DeviceInterfaceData
{
ULONG lastError = GetLastError();
printf("No SP_INTERFACE_DEVICE_DATA for this GUID instance\n");
printf("GetLastError() returns: %d\n", lastError);
SetupDiDestroyDeviceInfoList(info);
return NULL;
}
====================================
The pGuid contains the same exact GUID that was passed as the 2nd
parameter to IoRegisterDeviceInterface() in the device driver's
StartDevice().
I verified that this GUID exists in the registry under:
HKLM\SYSTEM\CurrentControlSet\Control\DeviceClasses
But nevertheless, while SetupDiGetClassDevs() succeeds,
SetupDiEnumDeviceInterfaces() fails with GetLastError() code of 259
(ERROR_NO_MORE_ITEMS).
Why?
What could possibly be the problem in such trivial call?
What is the "trick" that I am missing in properly using this function?
BTW, I also tried using a different GUID - the ClassGUID in the .inf
file, in case I misunderstood the meaning of the 3rd parameter to
SetupDiEnumDeviceInterfaces() but that one failed too. I am stumped.
How does one troubleshoot a problem like that?
Thanks,
Don
