Input: synaptics - LEN205b (ThinkPad T490) works with synaptics_intertouch=1

Input: synaptics - LEN205b (ThinkPad T490) works with synaptics_intertouch=1

[John Rosencutter]

Hello,

Per the kernel message, reporting that the touchpad below works
correctly over SMBus/RMI4 with psmouse.synaptics_intertouch=1.

Machine: Lenovo ThinkPad T490
PNP ID: LEN205b PNP0f13
Distro: Fedora 44
Kernel: 7.2.5-200.fc44.x86_64

dmesg before the change:
psmouse serio1: synaptics: Your touchpad (PNP: LEN205b PNP0f13) says
it can support a different bus. If i2c-hid and hid-rmi are not used,
you might want to try setting psmouse.synaptics_intertouch to 1 and
report this to linux-input@vger.kernel.org.
psmouse serio1: synaptics: Touchpad model: 1, fw: 10.32, id: 0x1e2a1,
caps: 0xf014a3/0x940300/0x12e800/0x500000, board id: 3471, fw id:
3972349

Results with intertouch enabled:
- Touchpad and TrackPoint both work
- Multi-finger gestures are much more reliable than under PS/2
- Both devices still work after suspend/resume

Please consider adding LEN205b to smbus_pnp_ids in
drivers/input/mouse/synaptics.c.

Thanks,
John

[PATCH] Input: synaptics - Add LEN205b entry to smbus_pnp_ids for ThinkPad T490

[Lovekesh Solanki]

Lenovo ThinkPad T490 has a Synaptics Touchpad that supports SMBus/RMI4
mode, but is not listed in smbus_pnp_ids table.

Add LEN205b to smbus_pnp_ids[] passlist.

Reported-by: John Rosencutter <rosencutter@gmail.com>
Closes: https://lore.kernel.org/all/CAOGuaRh025eKcBf9P8UrvtXNp68vQ0HVF2EbNMp-kpdaC1HNpA@mail.gmail.com/
Signed-off-by: Lovekesh Solanki <lovekeshsolanki00@gmail.com>
---
 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 2170bbe4c589..14484164f067 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -192,6 +192,7 @@ static const char * const smbus_pnp_ids[] = {
 	"LEN2054", /* E480 */
 	"LEN2055", /* E580 */
 	"LEN2058", /* E490 */
+	"LEN205b", /* T490 */
 	"LEN2068", /* T14 Gen 1 */
 	"SYN1221", /* TUXEDO InfinityBook Pro 14 v5 */
 	"SYN3003", /* HP EliteBook 850 G1 */
-- 
2.55.0

Re: [PATCH] Input: synaptics - Add LEN205b entry to smbus_pnp_ids for ThinkPad T490

[Dmitry Torokhov]

On Mon, Sep 21, 2026 at 01:37:30AM +0530, Lovekesh Solanki wrote:
> Lenovo ThinkPad T490 has a Synaptics Touchpad that supports SMBus/RMI4
> mode, but is not listed in smbus_pnp_ids table.
> 
> Add LEN205b to smbus_pnp_ids[] passlist.
> 
> Reported-by: John Rosencutter <rosencutter@gmail.com>
> Closes: https://lore.kernel.org/all/CAOGuaRh025eKcBf9P8UrvtXNp68vQ0HVF2EbNMp-kpdaC1HNpA@mail.gmail.com/
> Signed-off-by: Lovekesh Solanki <lovekeshsolanki00@gmail.com>

Applied, thank you.

-- 
Dmitry