On Sat, 2018-06-02 at 14:14 +1000, Peter Hutterer wrote: > On 1/6/18 22:50 , Timur Kristóf wrote: > > On Thu, 2018-05-31 at 13:44 -0700, Laura Abbott wrote: > > > On 05/24/2018 04:13 PM, Timur Kristóf wrote: > > > > Hi, > > > > > > > > On the XPS 13 9360 and 9370 xinput sees two touchpads instead > > > > of > > > > one: > > > > ⎡ Virtual core pointer id=2 [master > > > > pointer (3)] > > > > ⎜ ↳ Virtual core XTEST > > > > pointer id=4 [slave pointer (2)] > > > > ⎜ ↳ DELL07E6:00 06CB:76AF > > > > Touchpad id=12 [slave pointer (2)] > > > > ⎜ ↳ SynPS/2 Synaptics > > > > TouchPad id=17 [slave pointer (2)] > > > > > > > > dmesg also gives me the following: > > > > > > > > [ 1.429811] psmouse serio1: synaptics: Your touchpad (PNP: > > > > DLL07e6 > > > > PNP0f13) says it can support a different bus. If i2c-hid and > > > > hid- > > > > rmi > > > > are not used, you might want to try setting > > > > psmouse.synaptics_intertouch to 1 and report this to > > > > linux-input@xxxxxxxxxxxxxxx. > > > > > > > > The Dell one is the real touchpad, the other one is an artifact > > > > of > > > > the > > > > psmouse driver. Weird touchpad freezes and jittering issues can > > > > be > > > > observed when both of these devices are there. The general > > > > advice > > > > on > > > > the web is to blacklist the psmouse driver. (This is also > > > > published > > > > by > > > > Dell as a .deb package which contains a config file doing just > > > > this.) > > > > > > > > However, on Fedora I cannot blacklist the psmouse driver > > > > because it > > > > is > > > > compiled built-in instead of as a module. Could you guys change > > > > the > > > > Fedora kernel config to compile it as a module instead? > > > > > > > > Thanks & best regards, > > > > Timur > > > > > > So assuming nobody else has objections, I think it's okay to at > > > least try this on rawhide and see if it uncovers any other > > > problems. > > > > > > Thanks, > > > Laura > > > > > > > Looking into this a bit more, the root cause of this issue is that > > the > > touchpad is wired up in such a way that it is accessible on both > > PS/2 > > and I2C. I2C is preferred and used by i2c-hid but at the same time > > the > > PS/2 interface is also picked up by psmouse. Thus, Xorg sees the > > two > > interfaces as two different devices. > > That is fairly standard and doesn't matter. This was also the case > for > earlier SMBus implementation but the common thing was that the PS/2 > device never actually sent events. So it was only an issue for some > tools that expected only one touchpad to exist (e.g. synclient). > Check with evemu-record whether the device sends events. if not, > then > Xorg is definitely not confused by it. If it does and both event > nodes > send events then yes, we have a kernel bug there. I've talked to Mario, a developer at Dell, and he pointed me to this freedesktop bug report: https://bugs.freedesktop.org/show_bug.cgi?id=101470 According to his description, there is actually no input coming from PS/2 but it is still (wrongly) picked up by syndaemon. To be honest, I'm not sure if Fedora uses syndaemon (I assume libinput is used for everything now?), but I can tell that the touchpad does jitter when the PS/2 device is there. I can also confirm that evemu-record doesn't see any input coming from the PS/2 device. > > Solution would be to somehow remove the psmouse-detected device > > node > > from the system when i2c-hid detects the same device. Is this > > possible? > > This is more an upstream discussion, CC-ing benjamin for details. > > I do recommend filing a bug with an evemu recording of a > freezing/jittering interaction. Lots of touchpad processing happens > in > userspace and this could be the cause of pressure thresholds set too > high. CC me on that bug and I can have a look. sudo libinput > debug-events --verbose will also show extra information including > things > when a touch ended based on its pressure information. I can try to reproduce the problem and see if I can make an evemu recording. What should I file the bug against (and where)? Unfortunately I'm not familiar with the components involved. Searching for libinput in the journal reveals a bunch of touch jump messages, which seem to be related to the problem: https://paste.fedoraproject.org/paste/MoZGqf25VpHjCLSYzTxdfw Best regards, Tim _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx/message/XT5BLMD4EGU7YDFJPCSWYNODRHXPCRLD/
