Archive for the 'Linux' Category

ThinkPad T440p X.org touchpad configuration

Sep 13, 2014

While the ThinkPad T440p is a pretty nice device (and finally also available with a quad-core CPU), its touchpad is definitely a step back compared to previous ThinkPad generations, especially for trackpoint users like me. With the default X.org touchpad configuration shipped with (K)ubuntu 14.04 it is nearly unusable (clicks cause subtle mouse movements, palm detection is horribly broken and using the trackpoint is no fun at all due to touchpad interference).

Fortunately, this can be improved a lot using plain configuration.

Posted in Hacking, Linux, Tech, Ubuntu by Thilo-Alexander Ginkel

Disabling IPv6 Privacy Extensions in Ubuntu

May 24, 2012

You may already have noticed (e.g., when your packet filter rules broke after the Ubuntu 12.04 upgrade): Ubuntu 12.04 is forcing IPv6 privacy extensions to be enabled by default. There is a setting in /etc/sysctl.d/10-ipv6-privacy.conf, but it is ignored by Network Manager, which is Ubuntu’s standard facility to establish network connections. At least with Kubuntu there seems to be no configuration option to change this.

Fortunately, one can turn off IPv6 privacy extensions on a per-connection basis by editing the connection details in /etc/NetworkManager/system/connections/: Just add the setting ip6-privacy=0 to the [ipv6] section of the connection file and you are done.

Posted in Linux, Ubuntu by Thilo-Alexander Ginkel

Fixing Double-Click Interval for Java Applications Under Linux

Dec 4, 2011

If you are using any Java applications (such as IntelliJ IDEA or RubyMine) under Linux / KDE you may have wondered why their response to double-clicks is somewhat sluggish or unreliable. As it turns out, Java (Swing) ignores KDE’s setting for the double-click interval, so Java uses a pretty short default (AFAIK ~200 ms).

To fix this, create a file named .Xresources in your home directory and add the following line:

*.multiClickTime: 500

Set its value to whatever interval you prefer (the example is using 500 ms).

Edit: JetBrains support just mailed me that the root cause is a bug in the JDK, reported in 2004 and fixed in Java 7 (doh!): http://bugs.sun.com/view_bug.do?bug_id=5076635

Posted in Java, KDE, Linux by Thilo-Alexander Ginkel

Printing to a Kyocera FS-1370DN via IPP/SSL under Linux

Nov 15, 2011

So I recently got a shiny new Kyocera FS-1370DN printer, which features a built-in NIC (and even supports IPv6). As I have multiple client PCs I wanted to actually use the printer’s network interface instead of wiring it up through USB. While not being strictly necessary in a SOHO network environment, I wanted to go for a protocol that supports encryption. Fortunately, the FS-1370DN supports IPP over SSL. The documentation on how to correctly address the printer through that protocol was scarce, though, and Google was not much of a help.

As I eventually figured out the right URL to use in CUPS:

ipp://<hostname>:443/printers/lp1?encryption=required

Apart from that you need to make sure that IPP over SSL is turned on (which you can’t using the printer’s built-in menu, but only through its web-based management UI [Basic -> Device Security -> Network Security -> IPP over SSL -> Unblock] and [Advanced -> Secure Protocols -> SSL -> On]).

Posted in Linux by Thilo-Alexander Ginkel

Reducing T420s Power Consumption under KDE/Linux

Oct 6, 2011

If you own a Lenovo ThinkPad T420s (or any recent-generation notebook with a Sandy Bridge CPU) with Intel HD 3000 Graphics, this information may help you to reduce the power consumption under KDE/Linux:

  • Intel HD 3000 Power-Saving: Enable the following Kernel command-line options: i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1

  • Force ASPM: Enable the pcie_aspm=force Kernel command-line option

  • In KDE, go to “System Settings” “Desktop Effects” “Advanced” and set the “Scale method” to “Crisp”.

Overall, this brings my T420s’s power consumption down below 9 W. For best results, use a recent Linux 3.1-rc pre-release.

Posted in KDE, Linux, OSS, Tech, Ubuntu by Thilo-Alexander Ginkel