Re: Why does libinput randomly calls my touchpad "SynPS/2 Synaptics" or "Synaptics TM2722-001"?

[Ottavio Caruso <ottavio2006-usenet2012@yahoo.com>]

Am Mi., 24. Apr. 2024 um 22:12 Uhr schrieb Lyude Paul <lyude@redhat.com>:
>
> FWIW: You might have better luck asking on some of the linux-input
> lists.... however
>
> you got lucky because it happens I've both worked on this stack and
> dealt with this exact machine haha. So I actually can answer this
> (response down below):


It turns out I didn't get any replies from anyone.

>
> On Tue, 2024-04-23 at 15:12 +0100, Ottavio Caruso wrote:
> > Hi,
> >
> > $ sudo X -version
> >
> > X.Org X Server 1.21.1.7
> > X Protocol Version 11, Revision 0
> > Current Operating System: Linux t440 6.1.0-20-amd64 #1 SMP
> > PREEMPT_DYNAMIC Debian 6.1.85-1 (2024-04-11) x86_64
> > Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.1.0-20-amd64
> > root=UUID=42a17f43-89bb-4523-952f-b8d97bcb4a30 ro quiet
> > xorg-server 2:21.1.7-3+deb12u7 (https://www.debian.org/support)
> > Current version of pixman: 0.42.2
> >
> > $ xinput --version
> > xinput version 1.6.3
> > XI version on server: 2.4
> >
> >
> >
> > On my old-ish Thinkpad T440, libinput alternatively calls my touchpad
> > "SynPS/2 Synaptics" or "Synaptics TM2722-001".
> >
> > $ grep Synaptics  /var/log/messages
> > Nov 26 09:12:38 t440 kernel: [18070.908478] psmouse serio1:
> > synaptics:
> > serio: Synaptics pass-through port at isa0060/serio1/input0
> > Nov 26 09:12:38 t440 kernel: [18070.947812] input: SynPS/2 Synaptics
> > TouchPad as /devices/platform/i8042/serio1/input/input35
> > Nov 26 20:33:19 t440 kernel: [27221.274488] rmi4_f01 rmi4-00.fn01:
> > found
> > RMI device, manufacturer: Synaptics, product: TM2722-001, fw id: 0
> > Nov 26 20:33:19 t440 kernel: [27221.314747] input: Synaptics TM2722-
> > 001
> > as /devices/pci0000:00/0000:00:1f.3/i2c-0/0-002c/rmi4-
> > 00/input/input39
> > Nov 27 19:28:05 t440 kernel: [    6.327297] psmouse serio1:
> > synaptics:
> > serio: Synaptics pass-through port at isa0060/serio1/input0
> > Nov 27 19:28:05 t440 kernel: [    6.366655] input: SynPS/2 Synaptics
> > TouchPad as /devices/platform/i8042/serio1/input/input2
> >
> > This without even rebooting or suspending the laptop.
>
> I don't think this has anything to do with libinput - Synaptics
> touchpads from around this generation will initially get setup as a
> PS/2 device during boot. But PS/2 mode is very limited (and somewhat
> buggy) functionality wise, so at the first opportunity the synaptics
> kernel driver will query the touchpad to figure out if it can be
> supported over RMI4. If so, the driver is supposed to switch the
> touchpad to that mode and discard the PS/2 device. So - it sounds like
> what's happening is that is broken for some reason.
>
> FWIW: I added linux-input to this thread along with our synaptics
> contact: Andrew Duggan.
>
> >
> > I have some scripts that disable or enable the touchpad (especially
> > when
> > I use the mouse) and I have to use tricks to accommodate this.
> >
> > Why does this happen in the first place? How can I troubleshoot it?
> >
> > Thanks.
> >
>
> --
> Cheers,
>  Lyude Paul (she/her)
>  Software Engineer at Red Hat
>


-- 
Ottavio Caruso

A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?