Touchpad Sensitivity for Kali 2.0 on an Acer C720 (Chromebook)

So, I didn't play with touchpad too much after installing Kali 2.0 on my Acer C720 Chromebook (see previous post). It turns out that the touchpad sensitivity to fingers is pretty high by default, which means that it doesn't always register finger movements and taps. There is a fix to this in the synaptics settings, and there a few ways to get to it.

First, the command synclient will show all of the related settings. Type it into a command line and see. The settings that control sensitivity are "FingerHigh" and "FingerLow". By default, FingerLow is set to 25 and FingerHigh is set to 30. So, use the command:

root@pc:~# synclient | grep -e 'Finger'

This will a handful of settings, including FingerHigh and FingerLow. To temporarily change them, use the command synclient <variable>=<value>.

root@pc:~# synclient FingerLow=6
root@pc:~# synclient FingerHigh=10


If you try to set FingerHigh=10 before moving FingerLow to 6, then the system will complain. That is because you are trying to set the "high" value (30->10) lower than the "low" value (25). So change low to 6, then high to 10.

Try other values and see if they work better. Once you have found good values, make them permanent by adding them to the /usr/share/X11/xorg.conf.d/50-synaptics.conf file.

Add the following section, or just the missing lines if it is already there:

Section "InputClass"
        Identifier "touchpad catchall"
        Driver "synaptics"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
        Option "FingerLow" "10"
        Option "FingerHigh" "16"
EndSection

My file already had the first three lines, so I just had to insert:

        MatchDevicePath "/dev/input/event*"
        Option "FingerLow" "10"
        Option "FingerHigh" "16"

After that, restart X11. I just rebooted the system. Don't forget to put the "*" at the end of the MatchDevicePath line!

Kali 2.0 x64 on Acer c720

Kali 2.0 came out a few days ago, so I wanted to install it and see if the touchpad and suspend quirks had been worked out for the Acer c720. See previous posts to see how to replace the c720 firmware or install an alternate OS.

I downloaded the Kali 2.0 x64 version and created a bootable USB using Rufus 2.2. I then installed it on the Acer by hitting escape at boot to bring up a boot menu. I selected the USB drive and then the install option. I did not use the graphical install.

There was one problem during install where it complained that it could not mount the CDROM (or a similar error). The fix was simply to remove the USB drive, reinsert it, wait a second for it to initialize, and then tell the scrip to try and mount it again. It was clear sailing after that.

The install went smoothly. I was able to suspend using the power button, but closing the lid still does not suspend. Resume worked fine. However, when shutting down, there was an error compaining about ehci-pci port resume error. It just kept going, and I had to shutdown by holding the power button.

I tried the old fixes for sound and ehci with a script in the sleep.d directory, but that didn't seem to do anything. I then modified the grub file in /etc/default/grub.

I changed
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet modprobe.blacklist=ehci_hcd,ehci_pci"

Then, I had to rebuild using
# update-grub
# update-grub2

This seemed to resolve the error after suspend, but I haven't tested it with bluetooth or usb devices yet. Also, suspend using the lid seems to work now too. I'm not sure why it didn't before. I might have updated a power setting that got it to work.