On Mon, 20 Jun 2016 22:55:35 +0200 Gaëtan Harter via arch-general <arch-general@xxxxxxxxxxxxx> wrote: > 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. > 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. Hello Gaëtan, thanks for your response! I just downgraded the kernel to 4.5.4-1, which I had installed before the 4.6 versions and was still available in my pacman cache. This seems to resolve the issue for me, too. Did you report a bug? I don't think I feel comfortable with bisecting the kernel on my productive system right now, but I'd still like to update my kernel in the future ;) -- Grüße/Regards Manuel Groß
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