[PATCH libinput] touchpad: add a special quirk for the Lenovo x220 with updated firmware

[Peter Hutterer]

If an x220 is updated to the touchpad firmware version 8.1, the touchpad
suffers from the same issues as the x230 and needs custom acceleration code.
Unfortunately we cannot detect this otherwise, so it is left to the user as a
custom hwdb setting.

https://bugzilla.redhat.com/show_bug.cgi?id=1264453

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 doc/device-configuration-via-udev.dox | 18 ++++++++++++++++++
 src/evdev-mt-touchpad.c               |  3 ++-
 src/evdev.c                           |  1 +
 src/evdev.h                           |  1 +
 udev/90-libinput-model-quirks.hwdb    | 12 ++++++++++++
 5 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/doc/device-configuration-via-udev.dox b/doc/device-configuration-via-udev.dox
index f615cc1..7987073 100644
--- a/doc/device-configuration-via-udev.dox
+++ b/doc/device-configuration-via-udev.dox
@@ -117,4 +117,22 @@ defaults or any other reason. The effects of setting these properties, the
 format of the property and the value of the property are subject to change
 at any time.
 
+ at subsection model_specific_configuration_x220fw81 Lenovo x220 with touchpad firmware v8.1
+
+The property <b>LIBINPUT_MODEL_LENOVO_X220_TOUCHPAD_FW81</b> may be set by a
+user in a local hwdb file. This property designates the touchpad on a Lenovo
+x220 with a touchpad firmware version 8.1. When this firmware version is
+installed, the touchpad is imprecise. The touchpad device does not send
+continuos x/y axis position updates, a behavior also observed on its
+successor model, the Lenovo x230 which has the same firmware version. If the
+above property is set, libinput adjusts its behavior to better suit this
+particular model.
+
+The touchpad firmware version cannot be detected automatically by libinput,
+local configuration is required to set this property. Refer to the libinput
+model quirks hwdb for instructions.
+
+This property must not be used for any other purpose, no specific behavior
+is guaranteed.
+
 */
diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index 8e2a5c5..8014cc9 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -1566,7 +1566,8 @@ tp_init_accel(struct tp_dispatch *tp, double diagonal)
 	tp->accel.x_scale_coeff = (DEFAULT_MOUSE_DPI/25.4) / res_x;
 	tp->accel.y_scale_coeff = (DEFAULT_MOUSE_DPI/25.4) / res_y;
 
-	if (tp->device->model_flags & EVDEV_MODEL_LENOVO_X230)
+	if (tp->device->model_flags & EVDEV_MODEL_LENOVO_X230 ||
+	    tp->device->model_flags & EVDEV_MODEL_LENOVO_X220_TOUCHPAD_FW81)
 		filter = create_pointer_accelerator_filter_lenovo_x230(tp->device->dpi);
 	else
 		filter = create_pointer_accelerator_filter_touchpad(tp->device->dpi);
diff --git a/src/evdev.c b/src/evdev.c
index 83b1c20..85ca640 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -1651,6 +1651,7 @@ evdev_read_model_flags(struct evdev_device *device)
 		enum evdev_device_model model;
 	} model_map[] = {
 		{ "LIBINPUT_MODEL_LENOVO_X230", EVDEV_MODEL_LENOVO_X230 },
+		{ "LIBINPUT_MODEL_LENOVO_X220_TOUCHPAD_FW81", EVDEV_MODEL_LENOVO_X220_TOUCHPAD_FW81 },
 		{ "LIBINPUT_MODEL_CHROMEBOOK", EVDEV_MODEL_CHROMEBOOK },
 		{ "LIBINPUT_MODEL_SYSTEM76_BONOBO", EVDEV_MODEL_SYSTEM76_BONOBO },
 		{ "LIBINPUT_MODEL_SYSTEM76_GALAGO", EVDEV_MODEL_SYSTEM76_GALAGO },
diff --git a/src/evdev.h b/src/evdev.h
index 75a2cb6..09c05e9 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -108,6 +108,7 @@ enum evdev_device_model {
 	EVDEV_MODEL_SYNAPTICS_SERIAL_TOUCHPAD = (1 << 9),
 	EVDEV_MODEL_JUMPING_SEMI_MT = (1 << 10),
 	EVDEV_MODEL_ELANTECH_TOUCHPAD = (1 << 11),
+	EVDEV_MODEL_LENOVO_X220_TOUCHPAD_FW81 = (1 << 12),
 };
 
 struct mt_slot {
diff --git a/udev/90-libinput-model-quirks.hwdb b/udev/90-libinput-model-quirks.hwdb
index cf4fbfa..814ec40 100644
--- a/udev/90-libinput-model-quirks.hwdb
+++ b/udev/90-libinput-model-quirks.hwdb
@@ -67,6 +67,18 @@ libinput:name:Atmel maXTouch Touchpad:dmi:*svn*GOOGLE*:pn*Samus*
 # LENOVO
 ##########################################
 
+# X220 after a bios update updating the touchpad firmware version to 8.1
+# See https://bugzilla.redhat.com/show_bug.cgi?id=1264453 for details
+# If the touchpad is unresponsive and dmesg includes this line
+# 	psmouse serio1: synaptics: Touchpad model: 1, fw: 8.1 [...]
+# then copy the two lines below into a new file
+# /etc/udev/hwdb.d/90-libinput-x220-touchpad-fw81.hwdb, then run
+# sudo udevadm hwdb --update and reboot.
+#
+# Copy the two lines below:
+#libinput:name:SynPS/2 Synaptics TouchPad:dmi:*svnLENOVO:*:pvrThinkPadX220*
+# LIBINPUT_MODEL_LENOVO_X220_TOUCHPAD_FW81=1
+
 # X230 (Tablet)
 libinput:name:SynPS/2 Synaptics TouchPad:dmi:*svnLENOVO:*:pvrThinkPadX230*
  LIBINPUT_MODEL_LENOVO_X230=1
-- 
2.5.0