Finally I have an environment where I can test my kernel code. On Mon, 31 Oct 2022 at 10:29, Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> wrote: > For identifying the GLOW device you should be adding an id in the > table of hid-logitech-hidpp, with a driver data that tells the driver > to look for 0x1990. > > > > > > - you need to add a hook in connect_event to register the led class > > > device that will hook on to the actual LED of the device Sadly my tests did not go very far. The code fails already when calling the `probe` callback (`hidpp_probe`). When it calls into `hidpp_root_get_protocol_version` it seems to receive `HIDPP_ERROR_RESOURCE_ERROR`. Which then leads to an error message: Device not connected Upon looking at `HIDPP_ERROR_RESOURCE_ERROR` (9) there is no documentation what it means in code. >From a look into the docs it says that 9 is UNSUPPORTED error for 2.0 devices. Thus I am wondering how the code knows that it is a problem with connectivity. Couldn't it also mean that the device is not supporting getting the protocol version? And why is protocol version only enforced for non unifying devices?
