Input: trackpoint - assume 3 buttons when buttons detection fails

commit 293b915fd9bebf33cdc906516fb28d54649a25ac upstream.

Trackpoint buttons detection fails on ThinkPad 570 and 470 series,
this makes the middle button of the trackpoint to not being recogized.
As I don't believe there is any trackpoint with less than 3 buttons this
patch just assumes three buttons when the extended button information
read fails.

Signed-off-by: Oscar Campos <oscar.campos@member.fsf.org>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/input/mouse/trackpoint.c b/drivers/input/mouse/trackpoint.c
index bd5c176c7a2d957804513911a99268ff48d541af..18c416c43ac4c721c81dc64deb11ad6d1392208a 100644 (file)
--- a/drivers/input/mouse/trackpoint.c
+++ b/drivers/input/mouse/trackpoint.c
@@ -377,8 +377,8 @@ int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
                return 0;
 
        if (trackpoint_read(&psmouse->ps2dev, TP_EXT_BTN, &button_info)) {
-               psmouse_warn(psmouse, "failed to get extended button data\n");
-               button_info = 0;
+               psmouse_warn(psmouse, "failed to get extended button data, assuming 3 buttons\n");
+               button_info = 0x33;
        }
 
        psmouse->private = kzalloc(sizeof(struct trackpoint_data), GFP_KERNEL);