On Mon, Jun 20, 2016 at 7:17 PM, Manuel Groß <mgr@xxxxxxxxxxxxx> wrote: > Hello there, > > I currently experience a weird keyboard lag issue which I yet failed > to resolve. I had some help looking into it a bit (and obviously > searched the web), but we couldn't identify the speficic problem. I hope > someone could provide me pointers or hints on what to test out. > > I have a Thinkpad x250 running Arch Linux with Openbox and X11 on it. > I use systemd-logind to log in, so X is started with the 'exec > openbox-session' from my xinitrc. Not from some fancy lightdm or so. > I do not have a certain date since when the issue occurs, but it has > probably been a little over a month. I didn't make any major changes to > my system then, and I do update regularly. This didn't occur when I set > up the system. > > The issue is, that on some, certain programs, the keyboard input > 'arrives' too late, with delays up to 1-2s. In other programs, this > never happens at all. And in rare occasions, it is even fine for > programs, in which I experience the problem. > I checked logs at obvious locations, but neither the systemd journal, > dmesg or the Xorg log were screaming 'I have an issue here'. > The trackpoint always works as excpected and the touchpad is disabled. > > Programs where the delay occurs: > * sakura > * sublime > * wireshark (qt5 version) > > Programs which are fine: > * claws-mail > * geany > * xterm > * chromium > > The delay also never occurs in the system shell (Alt+F2) and xterm, so > it's not the shell or oh-my-zsh. > The program lists suggests, that it is not a problem due to a specific > version of GTK or QT, since programs using either library (or none of > them) are affected. > > I tried using 'libinput' instead of 'evdev' as a keyboard driver, > but the change had no effect (I double checked the Xorg log which driver > was actually used). > In 'xev', all keystrokes arrive immediately. > > So seems not to be the kernel or the driver, nor a specific gtk or qt > library. > The next thing to test would probably be the xlib and the libxcb > themselves. So I used 'downgrader' to downgrade each a few revisions > (also their lib32-libraries) and checked for a change, without success. > > I don't know what to try next. Does anyone of you have an idea or > already solved a similar issue? I'd appreciate any help on this. > -- > Grüße/Regards > Manuel Groß > Hi Manuel, I have a Thinkpad T440p and I have the same issue with kernel 4.6, with both 4.6.2-1 and 4.6.1-XX versions. There is no issue with lts kernel 4.4.13-1. >From what I experienced, gnome-terminal is impacted, and I think also firefox. Regards, Gaëtan Harter
