Bug#740042: linux: The module chromeos_laptop is not enabled in kernel 3.13, needed to enable touchpad on chromebooks

[David Shao <davshao@gmail.com>]

On Tue, Feb 25, 2014 at 6:32 AM, Ben Hutchings <ben@decadent.org.uk> wrote:
> On Mon, 2014-02-24 at 22:45 -0800, David Shao wrote:

>> I modified cros-haswell-modules.sh for 3.13 following the directions from:
>>
>> https://wiki.archlinux.org/index.php/Acer_C720_Chromebook
>
> Oh, so further source changes are needed to support it properly?
>
>> and pulling in the modified /boot/config-3.13-1-amd64-chrome for the config.
>>
>> Note that the module is built and installed in a new directory
>> platform/chrome not platform/x86.
>
> That doesn't matter when building a package.

The Arch Linux modifications for 3.13 can be found at:

http://pastie.org/8763538

The patches used are the same as for 3.12 in this version:

# Use Benson Leung's post-Pixel Chromebook patches:
# https://patchwork.kernel.org/bundle/bleung/chromeos-laptop-deferring-and-haswell/
echo "Applying Chromebook Haswell Patches..."
for patch in 3078491 3078481 3074391 3074441 3074421 3074401 3074431 3074411; do
  wget -O - https://patchwork.kernel.org/patch/$patch/raw/ | sed
's/drivers\/platform\/x86\/chromeos_laptop.c/drivers\/platform\/chrome\/chromeos_laptop.c/g'|
patch -p1
done

The paradox is I keep reading claims such as:

https://plus.google.com/114358706658341629084/posts/Q9B4DiqWZ5E

"As far as I can see, 3.13 has all the patches(including touchscreen
model and touchpad) except the patch that defines what hardware config
to use for the c720[p](the one in the chromeos_laptop.c file)."

Yet the working 3.13 script uses all the 3.12 patches and uses the
chrome subdirectories whereas in 3.12 the module used to be built and
installed under x86.

There is also an additional patch for the touchscreen c720p version of
the Acer Chromebook, that I can't test because I don't have the
touchscreen, discussed at:

https://bugzilla.redhat.com/show_bug.cgi?id=1045821

To summarize, to get the touchscreen Acer Chromebook c720p working out
of the box with Debian, at least three additional patches need to be
applied.  There is a claim that six patches have already been applied
upstream, but basically that should be ignored and the original six
patches should still be applied only modified to be applied in a new
subdirectory.

And in addition there are additional scripts discussed at

https://wiki.archlinux.org/index.php/Acer_C720_Chromebook

that need to be installed for say suspend to work.  There are two
different ways to implement these scripts, one way I believe is more
recent systemd related.  I use a different version from:

https://bbs.archlinux.org/viewtopic.php?pid=1364376#p1364376

For this second solution there is a new script:

/etc/pm/sleep.d/05_Sound

edited /etc/rc.local, and edited /etc/default/grub, the grub
modification I use being

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash tpm_tis.force=1"

and not the longer version discussed at the Arch Linux wiki.

>From the Arch Linux wiki I for better trackpad usability I add:

/etc/X11/xorg.conf.d/50-cros-touchpad.conf
Section "InputClass"
    Identifier      "touchpad peppy cyapa"
    MatchIsTouchpad "on"
    MatchDevicePath "/dev/input/event*"
    MatchProduct    "cyapa"
    Option          "FingerLow" "10"
    Option          "FingerHigh" "10"
EndSection