Incorrect 60-evdev.hwdb entry for T490 trackpad

[ianhi]

systemd version the issue has been seen with

245

Used distribution

PopOS 20.04

The current entry for the T490 trackpad:

systemd/hwdb.d/60-evdev.hwdb

Lines 524 to 529 in b642dfc

	# Lenovo Thinkpad T490
	evdev:name:SynPS/2 Synaptics TouchPad:dmi:*:svnLENOVO:*pvrThinkPadT490:*
	EVDEV_ABS_00=::57
	EVDEV_ABS_01=::33
	EVDEV_ABS_35=::57
	EVDEV_ABS_36=::33

Was introduced on the basis of a touchpad-edge-detector report from https://gitlab.freedesktop.org/libinput/libinput/issues/402. However, the incorrect touchpad dimensions (78x108 mm) were used with touchpad-edge-detect. I measured and found the correct dimensions to be 100x68 mm which is the same as in this article and a later post in the same libinput issue.

This swap of the x and y dimensions results in much faster movement in y than in x. I ran touchpad-edge-detect 100x68 /dev/input/event5 giving:

User-specified touchpad size: 100x68mm
Calculated ranges: 4412/3533

Suggested udev rule:
# <Laptop model description goes here>
evdev:name:SynPS/2 Synaptics TouchPad:dmi:bvnLENOVO:bvrN2IET80W(1.58):bd11/26/2019:svnLENOVO:pn20N2CTO1WW:pvrThinkPadT490:rvnLENOVO:rn20N2CTO1WW:rvrSDK0J40709WIN:cvnLENOVO:ct10:cvrNone:*
 EVDEV_ABS_00=1266:5678:44
 EVDEV_ABS_01=1161:4694:52
 EVDEV_ABS_35=1266:5678:44
 EVDEV_ABS_36=1161:4694:52

Changing these values in /lib/udev/hwdb.d/60-evdev.hwdb fixed the faster movement in y than in x for me.

Per the gitlab issue cc @whot

[JohnPucciarelli]

Thanks for fixing this! For anyone interested in applying the changes while waiting for this fix to get upstreamed:

Change values in /lib/udev/hwdb.d/60-evdev.hwdb to match those in the pull-request.

Then to apply the changes (see: http://who-t.blogspot.com/2019/02/adding-entries-to-udev-hwdb.html):

systemd-hwdb update
udevadm control --reload-rules
udevadm trigger

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