Bug 43482

Summary:	elantech: Touchpad always reports 3 finger tap as 1 finger tap
Product:	xorg	Reporter:	Ahmed Shams <AhmedKhattabShams>
Component:	Input/synaptics	Assignee:	Peter Hutterer <peter.hutterer>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	medium	CC:	AhmedKhattabShams
Version:	unspecified
Hardware:	Other
OS:	Linux (All)
URL:	https://launchpad.net/bugs/873482
See Also:	https://launchpad.net/bugs/873482
Whiteboard:
i915 platform:		i915 features:

Description Ahmed Shams 2011-12-02 16:46:44 UTC

On behalf of Jason Conti:
https://launchpad.net/bugs/873482

I have an ETPS/2 Elantech touchpad in my Asus Eeepc and since installing oneiric, 3 finger taps always registers as whatever TapButton1 is set to in synclient. The touchpad would appear to use the version 2 protocol, since it has 6 bytes per packet.

I reported this issue against linux instead of xserver-xorg-input-synaptics because booting into the natty kernel (2.6.38-11) in oneiric fixes the issue and 3 finger taps work correctly.

As further testing, I built a kernel from linus's git (so it doesn't have the elantech version 3 patches included with the latest oneiric kernels), and 3 finger tap still didn't work, so my guess it is a problem with one of the changes to include the new kernel multi-touch code. I don't know if this means there is a bug in this new code, or some issue with xserver-xorg-input-synaptics and the new code.

I reverted the multi-touch changes in drivers/input/mouse/elantech.{c,h} (back to the version in 2.6.38, still need to figure out exactly where the changes were introduced), rebuilt just the psmouse module and 3 finger tap works correctly again, so if it is a kernel problem, it would appear to be localized to just that module.

I will continue to investigate, any assistance is appreciated.
#

Comment 1 Peter Hutterer 2011-12-18 21:42:21 UTC

does this touchpad actually report BTN_TOOL_TRIPLETAP when you're clicking with three fingers?

Comment 2 Jason Conti 2012-03-14 09:57:20 UTC

Sorry, I posted this reply from launchpad a while ago, but it seems to never have synced. This bug can probably be closed, the problem was in the ubuntu patches, not the upstream code, and it seems to be fixed in the version included in 12.04. I'll include the original comment below.

Original Comment:

Yes, there is a log of the events from several triple taps here https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-synaptics/+bug/873482/+attachment/2544802/+files/input-events-oneiric.txt if you are curious, however, I do not believe the bug is in the upstream code. Ubuntu has a set of patches on top which tries to count the number of fingers in an event, ignoring in most cases what the kernel sends, but elantech devices do not send enough information for triple taps to register properly with this method. Sorry for the confusion.

Comment 3 Peter Hutterer 2012-03-14 16:41:43 UTC

thanks. closing this bug, please reopen if you notice it again.

Comment 4 Brandon Watkins 2012-03-31 06:56:56 UTC

This has come back, and now seems to be an upstream issue with the recently merged 200_fix_four_tap.patch:
"And merged upstream now, so I guess it finally is an upstream bug. http://patchwork.freedesktop.org/patch/9628/ http://cgit.freedesktop.org/xorg/driver/xf86-input-synaptics/commit/?id=da461b91659d0c64aa6827e065aee2682116a57e (a week after I get the upstream bug closed...)"

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-synaptics/+bug/873482

This patch does not work with elantech touchpads, and causes 3 finger tap not to work.

Comment 5 Jason Conti 2012-04-02 13:12:54 UTC

This issue seems to be fixed with the patch at http://patchwork.freedesktop.org/patch/9719/

Comment 6 Peter Hutterer 2012-04-15 23:40:36 UTC

Closing again as per comment #5. Thanks for testing.

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