Bug 106489

Summary:	'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)
Product:	Wayland	Reporter:	mario.vukelic
Component:	libinput	Assignee:	Wayland bug list <wayland-bugs>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium	CC:	mario.vukelic, peter.hutterer
Version:	unspecified
Hardware:	x86-64 (AMD64)
OS:	All
URL:	https://bugs.launchpad.net/ubuntu/+source/libinput/+bug/1764097
Whiteboard:
i915 platform:		i915 features:
Attachments:	Output of sudo libinput-list-devices UdevDB.txt as produced by Ubuntu

Description mario.vukelic 2018-05-12 16:13:41 UTC

Created attachment 139525 [details]
Output of sudo libinput-list-devices

Touchpad worked perfectly with libinput 1.8.2 on Ubuntu 17.10.
With 1.10.4 on Ubuntu 18.04, touchpad becomes temporarily unresponsive during normal use.

The most reliable reproduction seems to perform a circular motion for a couple of seconds. The pointer will stop moving and the touchpad will stop responding to further input. Lifting the finger from the trackpad makes it work again until problem is triggered next time (which usually only takes a few seconds during use). 

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

Most likely the same issue was filed for Fedora and the apparent fix was to set
LIBINPUT_ATTR_PALM_SIZE_THRESHOLD=1000
See https://bugzilla.redhat.com/show_bug.cgi?id=1575260

I also filed a bug in Ubuntu:
https://bugs.launchpad.net/ubuntu/+source/libinput/+bug/1764097

Comment 1 mario.vukelic 2018-05-12 16:30:57 UTC

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.

Comment 2 mario.vukelic 2018-05-12 16:51:41 UTC

Created attachment 139526 [details]
UdevDB.txt as produced by Ubuntu

Let me know if you need anything else

Comment 3 Peter Hutterer 2018-05-14 23:19:40 UTC

Should be fixed now with

commit d7ff5a8f0d876b3125978fd357716ac0f5619de0
Author: Veli-Jussi Raitila <>
Date:   Fri May 11 12:26:16 2018 +0300

     Add quirk to fix spurious palm detections on MacBook Pro (13-inch, Mid 2009)

Comment 4 mario.vukelic 2018-05-15 06:14:45 UTC

Thank you very much.

In case it matters, the MacBookPro5,4 in this report is the 15" model, the MacBookPro5,5 in the Fedora bug report is the 13" model. They are both from the same mid-2009 generation.

Comment 5 Peter Hutterer 2018-05-15 06:51:16 UTC

thanks! shouldn't matter because they appear to have the same vid/pid for the touchpad (0x0237), so yours is captured by that match rule.

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