[PATCH AUTOSEL for 4.9 219/293] Input: psmouse - fix Synaptics detection when protocol is disabled

[Sasha Levin]

From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>

[ Upstream commit 2bc4298f59d2f15175bb568e2d356b5912d0cdd9 ]

When Synaptics protocol is disabled, we still need to try and detect the
hardware, so we can switch to SMBus device if SMbus is detected, or we know
that it is Synaptics device and reset it properly for the bare PS/2
protocol.

Fixes: c378b5119eb0 ("Input: psmouse - factor out common protocol probing code")
Reported-by: Matteo Croce <mcroce@xxxxxxxxxx>
Tested-by: Matteo Croce <mcroce@xxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/input/mouse/psmouse-base.c | 34 +++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index bee267424972..5cbf17aa8443 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -937,6 +937,21 @@ static void psmouse_apply_defaults(struct psmouse *psmouse)
 	psmouse->pt_deactivate = NULL;
 }
 
+static bool psmouse_do_detect(int (*detect)(struct psmouse *, bool),
+			      struct psmouse *psmouse, bool allow_passthrough,
+			      bool set_properties)
+{
+	if (psmouse->ps2dev.serio->id.type == SERIO_PS_PSTHRU &&
+	    !allow_passthrough) {
+		return false;
+	}
+
+	if (set_properties)
+		psmouse_apply_defaults(psmouse);
+
+	return detect(psmouse, set_properties) == 0;
+}
+
 static bool psmouse_try_protocol(struct psmouse *psmouse,
 				 enum psmouse_type type,
 				 unsigned int *max_proto,
@@ -948,15 +963,8 @@ static bool psmouse_try_protocol(struct psmouse *psmouse,
 	if (!proto)
 		return false;
 
-	if (psmouse->ps2dev.serio->id.type == SERIO_PS_PSTHRU &&
-	    !proto->try_passthru) {
-		return false;
-	}
-
-	if (set_properties)
-		psmouse_apply_defaults(psmouse);
-
-	if (proto->detect(psmouse, set_properties) != 0)
+	if (!psmouse_do_detect(proto->detect, psmouse, proto->try_passthru,
+			       set_properties))
 		return false;
 
 	if (set_properties && proto->init && init_allowed) {
@@ -988,8 +996,8 @@ static int psmouse_extensions(struct psmouse *psmouse,
 	 * Always check for focaltech, this is safe as it uses pnp-id
 	 * matching.
 	 */
-	if (psmouse_try_protocol(psmouse, PSMOUSE_FOCALTECH,
-				 &max_proto, set_properties, false)) {
+	if (psmouse_do_detect(focaltech_detect,
+			      psmouse, false, set_properties)) {
 		if (max_proto > PSMOUSE_IMEX &&
 		    IS_ENABLED(CONFIG_MOUSE_PS2_FOCALTECH) &&
 		    (!set_properties || focaltech_init(psmouse) == 0)) {
@@ -1035,8 +1043,8 @@ static int psmouse_extensions(struct psmouse *psmouse,
 	 * probing for IntelliMouse.
 	 */
 	if (max_proto > PSMOUSE_PS2 &&
-	    psmouse_try_protocol(psmouse, PSMOUSE_SYNAPTICS, &max_proto,
-				 set_properties, false)) {
+	    psmouse_do_detect(synaptics_detect,
+			      psmouse, false, set_properties)) {
 		synaptics_hardware = true;
 
 		if (max_proto > PSMOUSE_IMEX) {
-- 
2.15.1