My SetupDiEnumDeviceInfo returns ERROR_NO_MORE_ITEMS for certain devices (C#)

I am trying to fetch power data for my devices(cm_power_data_s).
I am using the SetupDiGetDeviceRegistryProperty API to do so.
While this works fine for some devices, it doesn't work for others.
The data returned by SetupDiEnumDeviceInfo is null, and without this, I can't use SetupDiGetDeviceRegistryProperty.
I tried manually filling sp_devinfo_data by making a wmi query to get the class GUID, but SetupDiGetDeviceRegistryProperty doesn't return the buffer size with it (same as passing null data).
Can someone please help?
Here's my code:

uint SPDRP_DEVICE_POWER_DATA = 0x0000001E;
        int proptype;
        int size;
        //int D3, D2, D1, D3wake, cap = 0;
        DEVPROPKEY key = DEVPROPKEY.DEVPKEY_Device_PowerData;

        IntPtr hDevInfo = SetupDiGetClassDevs(IntPtr.Zero, DevID, IntPtr.Zero, DIGCF.DIGCF_ALLCLASSES | DIGCF.DIGCF_PRESENT | DIGCF.DIGCF_DEVICEINTERFACE);
        if (hDevInfo == (IntPtr)INVALID_HANDLE_VALUE)
        {
            throw new ArgumentNullException("invalidhandle");
        }
        SP_DEVINFO_DATA data = new SP_DEVINFO_DATA();
        data.cbSize = Marshal.SizeOf(data);

        SetupDiEnumDeviceInfo(hDevInfo, 0, ref data); // This data is empty for some devices
       // SetupDiGetSelectedDevice(hDevInfo, ref data);
        int aa = Marshal.GetLastWin32Error();

        bool b = SetupDiGetDeviceRegistryProperty(hDevInfo, ref data, SPDRP_DEVICE_POWER_DATA, out proptype, IntPtr.Zero, 0, out size);
        int a = Marshal.GetLastWin32Error();
        if (size == 0)
        {
                          return "";
         //   throw new ArgumentNullException("Power Data cannot be fetched");
        }

        IntPtr buffer1 = Marshal.AllocHGlobal(size);

        if (!SetupDiGetDeviceRegistryProperty(hDevInfo, ref data, SPDRP_DEVICE_POWER_DATA, out proptype, buffer1, size, out size))
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());

        }

I'm sure you've long since moved on since this question is from 18 months ago, but I just hit exactly this same problem. My googling brought me to your thread. Then I figured it out. So in case anyone else ever hits this, the problem is the flags that you supplied to SetupDiGetClassDevs.

You should have just given it the DIGCF_PRESENT flag. With all the flags you supplied you get back info for devices that aren't even there, leading to exactly the subsequent error you and I both got.