hwdb: fix ABS_PRESSURE axis range for Goodix GXTP5100 touchpad

The Goodix GXTP5100 touchpad (HID bus 0x0018, vendor 0x27C6, product
0x01E9), found in the Lenovo ThinkBook 16 G7+ IAH and ThinkPad X9 15
Gen 1, has a kernel driver bug where ABS_PRESSURE (axis 24 / 0x18) is
reported with min=0, max=0.

This invalid axis range causes libinput to reject the device with:
  "kernel bug: ABS_PRESSURE has min == max (both 0)"

The touchpad hardware itself is functional and reports valid ranges for
all other axes:
  ABS_X:  min=0, max=4149, resolution=31
  ABS_Y:  min=0, max=2147, resolution=27
  ABS_MT_POSITION_X/Y: valid ranges

Root cause: the kernel hid-multitouch driver applies a "GT7868Q report
descriptor fixup" to this device (the HID descriptor is malformed and
fails hid-generic probe with EINVAL). The fixup corrects most axes but
leaves ABS_PRESSURE with an invalid 0:0 range.

This hwdb entry overrides ABS_PRESSURE to a valid 0:255 range, allowing
libinput to accept and initialize the device.

Kernel version: 6.17.0-19-generic
Device path: /sys/bus/hid/drivers/hid-multitouch/0018:27C6:01E9.0001

diff --git a/hwdb.d/60-evdev.hwdb b/hwdb.d/60-evdev.hwdb
index 92b43fe1b29d13032fadda14f14bfa09f72362c1..767b63f83571db28aec56ec355027f020eb07695 100644 (file)
--- a/hwdb.d/60-evdev.hwdb
+++ b/hwdb.d/60-evdev.hwdb
@@ -421,6 +421,17 @@ evdev:name:Atmel maXTouch Touch*:dmi:bvn*:bvr*:bd*:svnGOOGLE:pnSamus:*
  EVDEV_ABS_35=::10
  EVDEV_ABS_36=::10
 
+#########################################
+# Goodix
+#########################################
+
+# Goodix GXTP5100 Forcepad (Lenovo ThinkBook 16 G7+ IAH, ThinkPad X9 15 Gen 1)
+# The kernel hid-multitouch driver reports ABS_PRESSURE with min==max==0,
+# an invalid range that causes libinput to reject the device entirely.
+# Override ABS_PRESSURE (axis 0x18=24) to a valid range.
+evdev:input:b0018v27C6p01E9*
+ EVDEV_ABS_18=0:255:0:0
+
 #########################################
 # Granite Devices Simucube wheel bases
 #########################################