Input: trackpoint - force 3 buttons if 0 button is reported

pyma1 · dtor · commit f5d07b9e9802 · 2018-01-22T16:23:17.000-08:00
Lenovo introduced trackpoint compatible sticks with minimum PS/2 commands. They supposed to reply with 0x02, 0x03, or 0x04 in response to the "Read Extended ID" command, so we would know not to try certain extended commands. Unfortunately even some trackpoints reporting the original IBM version (0x01 firmware 0x0e) now respond with incorrect data to the "Get Extended Buttons" command: thinkpad_acpi: ThinkPad BIOS R0DET87W (1.87 ), EC unknown thinkpad_acpi: Lenovo ThinkPad E470, model 20H1004SGE psmouse serio2: trackpoint: IBM TrackPoint firmware: 0x0e, buttons: 0/0 Since there are no trackpoints without buttons, let's assume the trackpoint has 3 buttons when we get 0 response to the extended buttons query. Signed-off-by: Aaron Ma <aaron.ma@canonical.com> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=196253 Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/mouse/trackpoint.c b/drivers/input/mouse/trackpoint.c
@@ -383,6 +383,9 @@ int trackpoint_detect(struct psmouse *psmouse, bool set_properties)
 	if (trackpoint_read(ps2dev, TP_EXT_BTN, &button_info)) {
 		psmouse_warn(psmouse, "failed to get extended button data, assuming 3 buttons\n");
 		button_info = 0x33;
+	} else if (!button_info) {
+		psmouse_warn(psmouse, "got 0 in extended button data, assuming 3 buttons\n");
+		button_info = 0x33;
 	}
 
 	psmouse->private = kzalloc(sizeof(struct trackpoint_data), GFP_KERNEL);

Original file line number	Diff line number	Diff line change
`@@ -383,6 +383,9 @@ int trackpoint_detect(struct psmouse *psmouse, bool set_properties)`
`383`	`383`	`if (trackpoint_read(ps2dev, TP_EXT_BTN, &button_info)) {`
`384`	`384`	`psmouse_warn(psmouse, "failed to get extended button data, assuming 3 buttons\n");`
`385`	`385`	`button_info = 0x33;`
	`386`	`+ } else if (!button_info) {`
	`387`	`+ psmouse_warn(psmouse, "got 0 in extended button data, assuming 3 buttons\n");`
	`388`	`+ button_info = 0x33;`
`386`	`389`	`}`
`387`	`390`
`388`	`391`	`psmouse->private = kzalloc(sizeof(struct trackpoint_data), GFP_KERNEL);`