kern/56998: synaptics touchpad tap-and-drag is broken

[campbell+netbsd%mumble.net@localhost]

>Number:         56998
>Category:       kern
>Synopsis:       synaptics touchpad tap-and-drag is broken
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Sep 05 12:45:00 +0000 2022
>Originator:     Taylor R Campbell
>Release:        9.99.99
>Organization:
Tha NatBSD Fonudetyon
>Environment:
NetBSD singbulli 9.99.99 NetBSD 9.99.99 (GENERIC) #134: Sat Sep  3 19:18:38 UTC 2022  root@keemun-b:/home/riastradh/netbsd/current/obj.amd64/sys/arch/amd64/compile/GENERIC amd64
>Description:
Normally, if I tap and then move my finger on the touchpad, it is as if I press a button and hold while moving my finger on the touchpad -- it grabs and drags, either moving a window or selecting text.  Tap twice times and move, and it selects text by words.  Three times, by lines.

In current, however, after I tap, once I put my finger down, the cursor freezes and doesn't move with my finger on the touchpad at all.  If I lift my finger, the cursor unfreezes and I can move it again with a new touch, but it doesn't drag or select anything while moving.

Relevant dmesg fragment:

[     1.069762] pckbd0 at pckbc1 (kbd slot)
[     1.069762] pckbc1: using irq 1 for kbd slot
[     1.069762] wskbd0 at pckbd0: console keyboard
[     1.069762] pms0 at pckbc1 (aux slot)
[     1.069762] pms0: Synaptics touchpad version 8.16
[     1.069762] pms0: Extended W mode, Passthrough, Palm detect, One button click pad, Multi-finger Report, Multi-finger, Reports max, Reports min
[     1.069762] pms0: Probed max coordinates right: 5676, top: 4690
[     1.069762] pms0: Probed min coordinates left: 1266, bottom: 1162
[     1.069762] pckbc1: using irq 12 for aux slot
[     1.069762] wsmouse0 at pms0 mux 0
>How-To-Repeat:
Tap touchpad and quickly touch down and move finger.
>Fix:
Yes, please!  I suspect this was probably broken in the synaptics rototills earlier this year.