Re: Two finger scrolling

[Brett Lymn <blymn%internode.on.net@localhost>]

On Tue, Mar 17, 2020 at 11:04:46AM +0000, nia wrote:
> 
> "Newer" thinkpads (x250, 2015...) have single-button clickpads with extra
> wired buttons. Until a few revisions ago these buttons couldn't be configured
> to act as regular mouse buttons and defaulted to acting as buttons 4 and 5.
> 

That is good...

> I haven't managed to get right clicks with the clickpad to work either,
> honestly. I was not sure how this was supposed to work until you explained
> it. To clarify, clicking the pad down with a single finger in the right
> area of the pad rarely results in a right click menu either. I worked
> around this by adding a knob to recognize the extra buttons as regular
> mouse buttons by default.
> 

OK, IIRC whether or not you get the click pad button emulation depends
on how the device reports itself - they are only there for one-button
click pads.

My main concern here is that you have converted all multi-touch into a
scroll event.

What W values were you getting when testing the two finger scroll?  Do
you have a copy of the "Synaptics PS/2 TouchPad Interfacting Guide, PN:
511-000275-01 Rev. B"?  I haven't located a later document but this one
does describe the various modes and what W means in those modes because,
unfortunately, it is overloaded depending on the mode the device is in.
I can send you a pdf of the document off list if you don't already have
a copy.

> I've got another laptop with a single button clickpad, and no buttons,
> but that's using the ims(4) driver which is significantly less useful.
> 

Is it an actual synaptics touchpad on the end of I2C?  I vaguely recall
that there is an ability to connect via I2C but I may be
mis-remembering.

> 
> The number of sysctl parameters with fairly magical values makes configuring
> this driver to a usable state a quite confusing affair. But yeah, the
> values are not fine-grained enough for me for that particular knob.

Yes, it is unfortunate that there are a lot of magical parameters there.
Hopefully most of them have sensible defaults, some are configured based
on reports from the trackpad itself but are exposed because sometimes
the trackpads lie.

Given what you are saying I am wondering if your trackpad was actually
in extended-W mode or not.  The W value, like a lot of the registers in
the trackpad, is overloaded and the numbers can mean different things
depending on what mode the trackpad is in and, even worse, the trackpad
won't tell you what mode it is in so you can't just test this.

-- 
Brett Lymn
--
Sent from my NetBSD device.

"We are were wolves",
"You mean werewolves?",
"No we were wolves, now we are something else entirely",
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