I develope a composite USB device of a flashdrive-endpoint and several HID/PID -endpoints/functions.
Therefore I wrote a bunch (4pcs with several report-ids each) of report descriptors to define the data packets for the different HID/PID usages. One goal is to use the generic driver of the operating system. So I need Windows to understand what I want to achieve.
The strange behaviour I strugle at is that all my report descriptors are working fine if they are loaded alone. Even compositions of two or three of them are working. But when I load all together the last few report-id-groups throw HID Error "10" from Windows.
When I then unload some report-id-groups before the failing report-id-groups the error ist gone.
So I assume that Windows cannot recognize some more (maybe round about 12?!) report-id-groups from one USB device with its generic standard driver?
But this makes no sense to me since the USB PID example from the USB Foundation page states that a PID device needs at least over 14 report-id-groups for one device. So Windows would never be capable of handling the PID standard, what I cannot believe.