Bug#924913: trackpad on L480 unusable after upgrade to testing

[Alois Schlögl <alois.schloegl@ist.ac.at>]

On 3/18/19 7:46 PM, Romain Perier wrote:

On Mon, Mar 18, 2019 at 12:43:10PM +0100, Alois Schlögl wrote:

On 3/18/19 12:20 PM, Romain Perier wrote:

Hello,

On Mon, Mar 18, 2019 at 11:27:41AM +0100, Alois Schlögl wrote:

Source: linux
Severity: normal

Dear Maintainer,

   On a Lenovo L480 laptop, I've upgraded Debian from 9 (stretch) to 10
(testing).
   After the upgrade, the touchpad and the trackpoint was not usable
anymore.


   This already has some bug report here,
   https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1803600

   As a workaround, one can run the command,
       sudo sh -c 'echo -n "elantech">
/sys/bus/serio/devices/serio1/protocol'
   in order to use the touchpad. However, on a GUI Interface and without
   an external mouse, it's impossible to apply this workaround
  (switching to the terminal <CTRL>-<ALT>F1, login, and run the command
above might work)

   I expect to be able to use the touchpad just out of the box, not needing
   to run the above workaround

Could you :

- Test with the last kernel uploaded to unstable (4.19.0-4:4.19.28) and confirm or
  not is the problem still exists ?

Dear Romain


I upgraded the kernel and rebooted:

schloegl@debian10:~$ uname -a
Linux debian10 4.19.0-4-amd64 #1 SMP Debian 4.19.28-2 (2019-03-15)
x86_64 GNU/Linux


With this kernel the trackpoint is working, the trackpad is still not
usable.

(This improves the situation because now at least one pointer device is
available).

Good, we did some progress :)

- According to the bug on launchpad and to the fix pushed upstream, the
  fix seems to be an hardware quirks, could you give me the output of the
  following command :
  $ /sys/bus/serio/devices/serio1/firmware_id

root@debian10:~# cat /sys/bus/serio/devices/serio1/firmware_id
PNP: LEN2036 PNP0f13

Could you test the patch attached to this reply ?
(if you don't know how to do this, I can provide support)

Regards,
Romain

I tried to followed these instructions:

https://kernel-team.pages.debian.net/kernel-handbook/ch-comm

4.5. Building a custom kernel from Debian kernel source

Specifically using the patched the sources,

scripts/config --disable MODULE_SIG
scripts/config --disable DEBUG_INFO
make clean make deb-pkg



and ended up with a kernel that does not boot (missing HD audio firmware),

Which procedure do you recommend to build and install a modified kernel ?

Regards,

  Alois