[ALPS i2c Touchpads] Palm detect pressure is too easy to trigger so that the cursor stalled

[Kai-Chuan Hsieh]

[Impact]

 * ALPS new i2c touchpads have capabilities for reporting ABS_PRESSURE and
   ABS_MT_PRESSURE event, However, it is very easy to over the default
   palm detect by pressure threshold 130. When the threshold is achieved,
   the cursor will be stalled, and not be able to keep following the
   finger's movement.

[Test Case]

 * For touchpad vid 0488, and have pressure capabilities.

   The pressure capability can be easily obtain by evtest tool, there
   should be ABS_PRESSURE and ABS_MT_PRESSURE event in ABS event type.

   Test step:
   Install libinput-tools
   1. $ sudo apt install libinput-tools
   2. $ sudo libinput measure touchpad-pressure
   3. Generally move the finger, the pressure max should not exceed the
      palm pressure detect threshold

[Regression Potential]

 * It only impacts ALPS i2c models
 * It won't impact the touchpad without capability to report pressure event.
 * For those touchpad with pressure capability will make the palm detect
   pressure be less sensitive. However, ALPS said its firmware can support
   firmware labeling palm detection, so it is okay that the palm detect
   pressure become less sensitive.

[Other Info]

 * The upstream commit has merged
   https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/505

[Kai-Chuan Hsieh (kchsieh)]

Upload debdiff.

[Łukasz Zemczak (sil2100)]

Sponsored for both groovy and focal.

[Kai-Chuan Hsieh (kchsieh)]

@sil2100

hello Lukasz,

May I know who can help to create deb and upload to queue?

Thanks,

[Launchpad Janitor (janitor)]

This bug was fixed in the package libinput - 1.16.1-1ubuntu1

---------------
libinput (1.16.1-1ubuntu1) groovy; urgency=medium

  * quirks: Customize ALPS i2c touchpad palm detect pressure threshold
    (LP: #1897553)

 -- Kai-Chuan Hsieh <email address hidden> Mon, 28 Sep 2020 18:29:24 +0800

[Timo Aaltonen (tjaalton)]

Hello Kai-Chuan, or anyone else affected,

Accepted libinput into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/libinput/1.15.5-1ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Kai-Chuan Hsieh (kchsieh)]

Verify on device SPT4-DVT1-C1, CID: 202008-28141. Touchpad hid: 0488:101A.

$ sudo apt install libinput-tools
$ sudo libinput measure touchpad-pressure

See the threshold become 180 by default.
Try to move finger on the touchpad. It won't exceed 180 by normal movement and usage.

[Launchpad Janitor (janitor)]

This bug was fixed in the package libinput - 1.15.5-1ubuntu0.1

---------------
libinput (1.15.5-1ubuntu0.1) focal; urgency=medium

  * quirks: Customize ALPS i2c touchpad palm detect pressure threshold
    (LP: #1897553)

 -- Kai-Chuan Hsieh <email address hidden> Mon, 28 Sep 2020 18:29:24 +0800

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for libinput has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.