'Apple touchpad bcm5974' unresponsive after "palm: touch size exceeded" on 'Apple MacBookPro5,4 (mid 2009)' with 1.10.4 (Ubuntu 18.04), worked fine with 1.8.2 (Ubuntu 17.10)

Status changed to 'Confirmed' because the bug affects multiple users.

Identical issue here on MacBook Pro (13-inch, Mid 2009) aka model MacBookPro5,5 using Ubuntu 18.04 final release.

I can also attest that this issue does not only affect Ubuntu. Fedora 27 exhibits the same symptoms for me.

Do not know if it is related, but simply resting one finger on the touchpad spams evtest with a load of ABS_MT_WIDTH_MAJOR, ABS_MT_WIDTH_MINOR and ABS_PRESSURE events. It seems like it somehow 'chokes' up due to this.

Trying to click-and-drag is a 100% reliable way to make things lock up.

Attached an example of evtest event spam when resting a finger on the touchpad for 10 seconds.

Deceivingly similar issue, and one that I also encountered, in Fedora here: https://ask.fedoraproject.org/en/question/120258/macbook-touchpad-becomes-unresponsive/

And a fix here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-abb147f32e

It would be nice to have this resolved as it pretty much renders Ubuntu unusable in affected Macbooks. The issue is reproducible on the 18.04 “LiveCD”.

The instructions the original reporter links to, for debugging touchpad issues in Ubuntu, is outdated. The way it seems to me, 18.04 Bionic Beaver uses the libinput drivers instead of synaptics by default. At least that is the case on the LiveCD. Therefore, this bug report is linked to the wrong component - understandable due to misleading documentation.

Furthermore, my initial analysis of the root cause was way off. The real issue is that the palm detection threshold for this particular model is set too low in libinput. Consequently, spurious palm detection events make the touchpad temporarily unresponsive. I've submitted a patch for this quirk upstream.

In my defense, the second paragraph seems to say that filing against xserver-xorg-input-synaptics is ok and bug triagers would assign it as needed. I really tried :) Thank you

Oh and is there a link to your upstream report, mailing list, or similar? Thanks

I know you tried :). I'm not assigning blame here as I would've done the same based on the documentation available.

According to my earlier comments, I ran into the same issue on Fedora, reported it here https://bugzilla.redhat.com/show_bug.cgi?id=1575260 and got excellent support. One of the libinput devs caught it and helped me out.

I would suggest stepping through the same process as I did by following the comments on that report, but filing a bug directly at https://bugs.freedesktop.org/enter_bug.cgi?product=wayland&component=libinput as it is an upstream issue. On Ubuntu, however, you might have to install some of the libinput debugging tools separately.

If we're lucky, and as our hardware is really similar, the same palm detection threshold might work for you as well like this:

# MacBookPro5,4 (Mid 2009)
libinput:name:bcm5974:dmi:*:svnAppleInc.:pnMacBookPro5,4:*
 LIBINPUT_ATTR_PALM_SIZE_THRESHOLD=1000

I'm not using Wayland but X though, would it still be libinput?

My understanding of the state of affairs is that while strictly a Wayland project (and hence categorized as such in their Bugzilla), libinput may also be used under Xorg with a separate wrapper driver. And that is what Ubuntu and many others are also doing.

But, naturally, I'm making assumptions about your particular setup. You can verify things by looking for a mention of 'libinput' in your Xorg startup logs.

Indeed, running "sudo libinput debug-events --verbose" results in:

 event6 POINTER_MOTION +11.04s 5.07/ -9.23
 event6 POINTER_MOTION +11.05s 16.95/ -2.91
 event6 POINTER_MOTION +11.06s 13.15/ -4.05
event6 - palm: touch size exceeded
event6 - palm: palm detected (touch size)
event6 - touch-size: end touch
event6 - button state: from BUTTON_STATE_AREA, event BUTTON_EVENT_UP to BUTTON_STATE_NONE

Upstream bug report: https://bugs.freedesktop.org/show_bug.cgi?id=106489

Running "sudo libinput measure touch-size" gives, for a single finger, max sizes between 580 (finger tip) and 1900 (when I deliberately put the first phalanx down flat).

"Normal" finger placement size is approx 850 to 950.
It seems to detect a palm event above 800, and this reliably reproduces the problem.

This bug was fixed in the package libinput - 1.11.1-1

---------------
libinput (1.11.1-1) unstable; urgency=medium

  * New upstream release. (LP: #1764097, #1746740, #1761365)
  * tests: Add a simple smoketest to check that linking to libinput
    works. Thanks, Simon McVittie! (Closes: #893391)
  * watch: Update upstream git repo location.
  * symbols: Updated.

 -- Timo Aaltonen <email address hidden> Thu, 21 Jun 2018 22:14:02 +0300