In a HID Report Descriptor, the correct encoding for Logical Maximum (255) is 26 FF 00, not 25 FF. The latter encodes Logical Maximum (-1). This is a common error, and some hosts rightfully reject it.
(The correct Logical Maximum is probably 221, because otherwise, the modifier keys could also be encoded in the key codes array, which is invalid for their usage type. A lot of production keyboards use 255 anyway, and hosts seem to accept that.)
In a HID Report Descriptor, the correct encoding for Logical Maximum (255) is
26 FF 00
, not25 FF
. The latter encodes Logical Maximum (-1). This is a common error, and some hosts rightfully reject it.(The correct Logical Maximum is probably 221, because otherwise, the modifier keys could also be encoded in the key codes array, which is invalid for their usage type. A lot of production keyboards use 255 anyway, and hosts seem to accept that.)