I have one of the affected keyboards with original, unmodified firmware,
so it should use the old "workaround" to function properly.
However, it seems that this keyboard does sometimes send REL_X events
when the middle button is pressed (contradicting the comment contained
in the patch).
Thus, with the patch the necessary workaround gets disabled. Once this
has happened, the middle button scrolling exhibits the known buggy behavior.
Explicitly, I can confirm the following values occur, leading to
disabling of the workaround:
cptkbd_data->middlebutton_state == 1
usage->type == 2 [i.e., EV_REL]
usage->code == 0 [i.e., REL_X]
This was tested with kernel 6.1.67 which contains this patch backported
(commit 6e2076cad8873cc2a9f96e4becab35425c3656dc).
The USB keyboard has been working fine for years with earlier kernels
and is identified by lsusb as:
ID 17ef:6047 Lenovo ThinkPad Compact Keyboard with TrackPoint
Best regards,
Uli
