On Wed, 9 Nov 2022 at 21:27, Andreas Bergmeier <abergmeier@xxxxxxx> wrote: > > 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? Also, looking into `supported_reports` turned out to be 2 (very long). Inside of `hidpp_root_get_protocol_version` it does upgrade SHORT to LONG if the former is not supported. On a whim I then added upgrade of LONG to VERY LONG if the former is not supported. Sadly, the results stayed the same.