Created attachment 1025058 [details] output of "evemu-record /dev/input/event5" showing wrong scroll behaviour near the bottom of the touchpad Problem with two fingers scrolling: sometimes when I scroll with two fingers, when reaching towards the bottom of the touchpad, instead of stopping the scrolling (or continuing to scroll down, through I have not seen a way to enable coasting with libinput), the scrolling may then start happening back up, which is quite annoying (see libinput-evemu-wrong-scroll-bottom-touchpad.log). It seems it happens if I then lift one of the two fingers before the other (it's obviously reproducible during a scroll down, the lower finger reaching the bottom of the pad, then when I lift the upper finger while leaving the lower finger on the touchpad; it also happens when one could say both fingers are lifted at the same time - so I guess in this last case, libinput is too sensitive, compared to my perception... ); weirdest is no such thing happens if I try it without the lower of the two fingers being near the bottom of the touchpad... First reported in bug #1219865: https://bugzilla.redhat.com/show_bug.cgi?id=1219865 Supposedly a touchpad bug, which Hans de Goede says should be detectable and circumvented in kernel.
Hi, Thanks for the bugreport, as discussed in bug 1219865, I believe that this is a touchpad bug which can be worked around at the kernel level. I've started a scratch F-22 kernel build which should fix this. I know your still on F-21 but the F-22 kernel should work fine there. You can find the scratch build here: http://koji.fedoraproject.org/koji/taskinfo?taskID=9750618 Please download the following rpms: kernel-4.0.3-...rpm kernel-core-4.0.3-...rpm kernel-modules-4.0.3-...rpm For your arch from there (note this is still building atm). Save them all to the same directory (which should not contain other rpms) and do: sudo rpm -ivh kernel-*.rpm From within that directory. Then boot into the new kernel and see if the problem is gone, and report the result back here. Thanks & Regards, Hans
Created attachment 1025727 [details] [PATCH] alps: Fix finger jumps on lifting 2 fingers on v7 touchpad
Hi Hans, Sorry for the late reply: was a bit busy these last few days, and I took the time to test your 4.0 kernel build. The rebound is mostly fixed now. Though there have been a few occasions when the up rebound happened again when scrolling down. It's so rare now that it's quite hard to reproduce, as shown by the much bigger log size this time (see evemu-rare-scroll-rebound.log). Much better now, so thanks a whole lot already!
Created attachment 1027447 [details] output of "evemu-record /dev/input/event5" showing (much rarer) wrong scroll behaviour near the bottom of the touchpad Had to spend some time to try and reproduce it, with the patched 4.0 kernel. So I scrolled down, and down, and down, unwillingly changed XFCE workspace through dragging the pointer down, started scrolling down again, until it happened.
Hi, Thanks for testing my patch. I've submitted it to the upstream kernel so that it can be merged there. As for the rare jump you still see, I can see that in the log, but it is caused by the touchpad actual reporting one finger moving up slightly just before the other finger is seen as released. Inlike the last time where the touchpad was clearly sending wrong coordinates, there is nothing we can do to fix this. Given that this is a quite minor issue, I believe it is best to wait for the patch to get into the Fedora kernels through the upstream kernel, rather then carrying it as a Fedora specific kernel patch, so I'm closing this bug. Regards, Hans
*** Bug 1225967 has been marked as a duplicate of this bug. ***