Hi Aaron, On Tue, Jan 02, 2018 at 09:57:55PM +0800, Aaron Ma wrote: > No, it is not a regression of this commit. > > ThinkPad X1 Yoga 2nd: > trackpoint (ID: 01) > > ThinkPad X1 Yoga 3rd: > trackpoint (ID: 03) > > Both laptop's trackpoints have the same behavior. > Writing "speed" of sysfs is failed. > > Override the ID and force loading drivers/input/mouse/elantech.c, > it causes too many failure and trackpoint stops work. Right, because it does not support Elantech *touchpad* protocol, that is not a surprise. > > The ID of "2.4.18 READ SECONDARY ID (x"E1")" in TrackPoint specification > does not indicate any other vendors but only trackpoint. Exactly. If ID does not match, it is not an IBM trackpoint device. > Elantech uses 0x03e9. > ALPS uses 0x00e6/0x00e7/0x00ec. > > Maybe the windows tool's is wrong like Linux driver before. I am not sure what you mean by that. Anyway, I played with my Carbons a bit, and it seems that the patch should indeed be reverted. I believe that neither the Elantech nor ALPS trackpoints support the IBM trackpoint protocol; none of the extended features (sensitivity, inertia, etc) work when we register them as TTPS/2 devices. They should continue to be registered as "Generic PS/2" as that's that they support. I understand that you want scroll mode working with trackpoints, but forcing them to pretend that they are TTPS/2 devices is not the proper way of doing that. Write udev rules that would set ID_INPUT_POINTINGSTICK property on all input devices connected to a pass-through serio ports on LENOVO devices, and you should be set (just make sure you cover both PS/2 pass-through and RMI pass-through options). Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
