This problem includes two situations, one is the jumpy cursor with Trackpoint, another is the trackpoint totally doesn't work.
This problem will randomly happen on both lenovo x230s and lenovo x240s with ubuntu Linux installed (any version). And on both machines, i kept the ubuntu rootfs and replaced the ubuntu linux kernel with upstream latest kernel, linux-3.8, linux-3.5, linux-3.0 and linux-2.6.38, the result didn't change, the problem still happened randomly. Then on the x230s, i installed windows7 home basic edition, CentOS-6.4-x86_64, openSUSE-12.3 and Fedora-Live-Desktop-x86_64-19-1, the result was same as the one got on the ubuntu Linux, this problem still can happen randomly. Through debugging, i found if i8042 want to communicate with trackpoint device, it will send the command or data to synaptics trackpad device first, then trackpad device send the command or data to trackpoint device through pass-through write, so we can say synaptic trackpad is the master device, trackpoint is the guest device. The problem is here, when i8042 send commands/datas to the guest devices, it will fail randomly both on x230s and x240s, let's suppose a situation, the host want to send a ENABLE(0xf4) to the guest device, but this command is failed to pass to guest device, so the trackpoint can't work totally. And i did debugging on lenovo T540 and lenovo x130e as well, the communication between i8042 and trackpoint device was very stable, never failed. Based on my investigation, i doubt more or less, this problem has some relation with hardware, according to the section 5.2.1 in the page 57 of Synaptics PS/2 TouchPad Interfacing Guide (http://www.synaptics.com/sites/default/files/511-000275-01_RevB.pdf), i doubt the guest port doesn't solder a proper pull-up resistor on lenovo x230s and lenovo x240s. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1226999 Title: [Lenovo X230s] Jumpy cursor with TPPS/2 IBM Trackpoint To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1226999/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
