From 26eb3d92c7a4d7adb1ae1740ca6e8e100b11d1ec Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rapha=C3=ABl=20Larocque?= Date: Thu, 10 Sep 2026 12:44:25 -0400 Subject: [PATCH] Input: synaptics - disable InterTouch on ThinkPad T440p (board id 2722) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Lenovo ThinkPad T440p (PNP ID LEN0036, board id 2722) has a Synaptics touchpad whose SMBus companion is not ready at boot and takes roughly 200 seconds to appear. During this window the touchpad and TrackPoint are completely unresponsive on approximately 50% of boots, making the machine unusable until the companion finally registers. The device is in the topbuttonpad_pnp_ids[] SMBus allowlist, so the kernel attempts to use SMBus/RMI4 mode by default. When the companion is not ready, psmouse_smbus_init() leaves breadcrumbs and returns -EAGAIN, the PS/2 fallback path is taken, but the device does not function properly until the companion appears and RMI4 takes over. Disable SMBus InterTouch for board id 2722 so the touchpad and TrackPoint work immediately via PS/2 from boot. Users can still force SMBus with psmouse.synaptics_intertouch=1 if needed. Tested-by: Raphaël Larocque Signed-off-by: Raphaël Larocque Link: https://patch.msgid.link/20260910164425.12832-1-rlarocque@disroot.org Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/synaptics.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c index 2170bbe4c589..a8ce89d41faa 100644 --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -1838,6 +1838,14 @@ static int synaptics_setup_intertouch(struct psmouse *psmouse, return -ENXIO; } + + /* Disable intertouch on known-broken board revisions */ + if (info->board_id == 2722) { + psmouse_info(psmouse, + "Disabling intertouch for board id %u\n", + info->board_id); + return -ENXIO; + } } psmouse_info(psmouse, "Trying to set up SMBus access\n");