Surface Slim Pen 2 on SLS have mis-behaviour on soft pressure of eraser when pen is hover/touch toward to screen

[NP-chaonay]

Let talking little bit of history.

This come from past issue: https://github.com/quo/iptsd/issues/5 (suggest that no need to serious reading it, it is long and not much readability, and it is in incompleted state but I just freezed for archiving the issue.)

I have archived (I mean freezed) the above issue due to transition from quo's iptsd to official iptsd.

And found later that some of problem mentioned there still occured on official iptsd.

so I decided to make new issue here.

BTW, I got suggestion form Dorain Stoll that: I should try this comment to solve DFT calib. which may cause the problem.

but as I remember, it dont work (see the test result I partially have noted there) but for sure, I will fully re-test it.

ok let talking about problem it self below

this happens on my SLS Ubuntu 22.04 (less-than-wek latest ithc and linux-surface iptsd)

I have tested in libinput debug-ui, it seem that eraser pressure sensors (it seem that if pressure sensor on eraser tip is not have received force, it not trigger erasing operation), when being pressed (not press eraser button, but trigger eraser sensor) , it trigger BTN_STYLUS (this event I think is not about eraser, so it should not be triggered when eraser is not point toward the touch screen) even eraser is not point toward screen.

this problem can redo by just point pen (not eraser tip) toward to screen, either hover or touch. and then press force on to eraser (without pressing the eraser button)

And when do that on UI component, it result in right click (according to mouse gnome-control-center) (some apps trigger what trigger by middle click, such as on link in google chrome)

PS: btw on link in web on firefox, it trigger right-click

[NP-chaonay]

BTW, I got suggestion form Dorain Stoll that: I should try https://github.com/quo/iptsd/issues/5#issuecomment-1159294604 to solve DFT calib. which may cause the problem.

for that I willl post the result once I have test, so stay tuned (I have to do acedemic degree, so maybe using long time for it btw)

updated: cancel test due to my desire to remove Ubuntu from system

[makinbacon21]

fyi i'm getting this on SLS as well and it's infuriating, so if there's any work i can help out with, i'd be glad to. I've had to disable xournal++'s button functionality because adding any button functions spams them when i'm trying to type.

[makinbacon21]

also should note that both buttons register as one button and cannot be mapped separately from other userspace apps for some reason

[makinbacon21]

Also re: the suggestion from quo, this has been moved to the config file so no recompilation is necessary for testing.

[makinbacon21]

Update: changing min button sense to 2000 fixed the issue--thanks @quo! if i get bored, i'll pr some way of having diff defaults per pen model, and maybe look into both buttons registering as button 2.

[StollD]

Is there a value that works well with different kinds of pens, that we could use as the default? IIRC @qzed mentioned that 3000 or 4000 seems to be OK with the older pens too.

[qzed]

See https://github.com/quo/iptsd/issues/5#issuecomment-1189681594 and thread. Maybe we should start collecting values across different devices and pens, so we can check if there's one that works for everything.

[makinbacon21]

I would love to do that--I'll try another pen soon.

[NP-chaonay]

BTW, I got suggestion form Dorain Stoll that: I should try quo#5 (comment) to solve DFT calib. which may cause the problem.

for that I willl post the result once I have test, so stay tuned (I have to do acedemic degree, so maybe using long time for it btw)

updated: cancel test due to my desire to remove Ubuntu from system

Now sorry to say that I desired to remove Ubuntu, so the test is cancelled

but as I read, it seem work

[joulewei]

I increased the ButtonMinMag from 2k in baby steps all the way to 10k. The issue became less frequent but never disappeared completely. So I went from 10k straight to 20k and it works now. I don't know if my pen is just malfunctioning or if there is such a variation in the pens.