Bug 55821

Summary:	Synaptics touchpad switches to scrolling mode under load
Product:	xorg	Reporter:	Jan Schmidt <thaytan>
Component:	Input/synaptics	Assignee:	Peter Hutterer <peter.hutterer>
Status:	RESOLVED DUPLICATE	QA Contact:
Severity:	normal
Priority:	medium	CC:	georgmueller
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Jan Schmidt 2012-10-10 03:01:57 UTC

I've been having this bug for a while, not sure when it started on my Lenovo x201, with Synaptics 1.6.2, Xorg 1.12.3, Linux 3.2.0.

Under heavy disk/system load, the touchpad mouse cursor will stop working, and any motion on the trackpad seems to be sent as scroll events. The keyboard nipple still works fine.

If I remove and reinsert the psmouse module, it works again... for a while.

Comment 1 Georg Müller 2012-10-25 13:14:43 UTC

I have the same issue with my thinkpad T510 since a while. I am currently using the 1.0.2 ubuntu package from quantal. The trackpoint or an attached USB mouse works fine when the touchpad shows this behavior.

Restarting X fixes it for me.

information from dmesg:
psmouse serio1: >synaptics: Touchpad model: 1, fw: 7.2, id: 0x1c0b1, caps: 0xd047b3/0xb40000/0xa0000
psmouse serio1: >synaptics: serio: Synaptics pass-through port at isa0060/serio1/input0
input: SynPS/2 Synaptics TouchPad as /devices/platform/i8042/serio1/input/input7



Is there a way to debug the state of the touchpad while running to provide some more information on this?

Comment 2 Danny 2012-12-27 20:11:28 UTC

I think when I experienced this bug:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=693726

under heavy load (I think the suspend/resume may just may another way to trigger the same problem), I also had the touchpad stuck in scrolling mode. Anything in your Xorg.0.log when you have this problem?

Comment 3 Danny 2013-01-10 13:38:40 UTC

This is possibly a duplicate of bug 52496.

Comment 4 Jan Schmidt 2013-01-10 21:25:23 UTC

Yep, seems likely. Similar Xorg output as in the last part of bug 52496 when it breaks: 

[227486.540] BUG: triggered 'if (priv->num_active_touches > priv->num_slots)'
[227486.540] BUG: ../../src/synaptics.c:3122 in UpdateTouchState()
[227486.540] 
[227486.540] Backtrace:
[227486.540] 0: /usr/bin/Xorg (xorg_backtrace+0x36) [0x7f15b2704c96]
[227486.540] 1: /usr/lib/xorg/modules/input/synaptics_drv.so (0x7f15acc5e000+0x3067) [0x7f15acc61067]
[227486.540] 2: /usr/lib/xorg/modules/input/synaptics_drv.so (0x7f15acc5e000+0x4733) [0x7f15acc62733]
[227486.540] 3: /usr/lib/xorg/modules/input/synaptics_drv.so (0x7f15acc5e000+0x7164) [0x7f15acc65164]
[227486.540] 4: /usr/bin/Xorg (0x7f15b2586000+0x8d907) [0x7f15b2613907]
[227486.540] 5: /usr/bin/Xorg (0x7f15b2586000+0xb1bd8) [0x7f15b2637bd8]
[227486.540] 6: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f15b18ae000+0xf030) [0x7f15b18bd030]
[227486.540] 7: /lib/x86_64-linux-gnu/libc.so.6 (__select+0x13) [0x7f15b068b553]
[227486.540] 8: /usr/bin/Xorg (WaitForSomething+0x190) [0x7f15b27020d0]
[227486.540] 9: /usr/bin/Xorg (0x7f15b2586000+0x52bb1) [0x7f15b25d8bb1]
[227486.540] 10: /usr/bin/Xorg (0x7f15b2586000+0x41ec5) [0x7f15b25c7ec5]
[227486.540] 11: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xfd) [0x7f15b05d5ead]
[227486.541] 12: /usr/bin/Xorg (0x7f15b2586000+0x4219d) [0x7f15b25c819d]
[227486.541] 
[227517.350] BUG: triggered 'if (priv->num_active_touches > priv->num_slots)'
[227517.350] BUG: ../../src/synaptics.c:3122 in UpdateTouchState()

*** This bug has been marked as a duplicate of bug 52496 ***

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