The Synaptics touchpad on Dell Inspiron 3521 (PNP ID DLL0597) advertises
InterTouch / SMBus support, but is not on the SMBus passlist, so the
driver falls back to PS/2 and logs a hint to try
psmouse.synaptics_intertouch=1.

Add DLL0597 to smbus_pnp_ids so InterTouch is enabled automatically on
this model (and other Dells that reuse the same PNP ID).

Hardware: Dell Inc. Inspiron 3521 (board 06RYX8, BIOS A07),
Synaptics fw 8.1 / board id 2382, firmware_id "PNP: DLL0597 PNP0f13".

Signed-off-by: Shashwat Agrawal <redacted>
---
 drivers/input/mouse/synaptics.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index c70502e24031..2170bbe4c589 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c

@@ -164,6 +164,7 @@ static const char * const topbuttonpad_pnp_ids[] = {
 #ifdef CONFIG_MOUSE_PS2_SYNAPTICS_SMBUS
 static const char * const smbus_pnp_ids[] = {
 	/* all of the topbuttonpad_pnp_ids are valid, we just add some extras */
+	"DLL0597", /* Dell Inspiron 3521 */
 	"DLL060d", /* Dell Precision M3800 */
 	"LEN0048", /* X1 Carbon 3 */
 	"LEN0046", /* X250 */

-- 
2.54.0