Bug 101196

Summary:	Lenovo Yoga 720 (15") touchpad not ignored by kernel drivers
Product:	Wayland	Reporter:	n.devaucleroy
Component:	libinput	Assignee:	Wayland bug list <wayland-bugs>
Status:	RESOLVED NOTOURBUG	QA Contact:
Severity:	major
Priority:	medium	CC:	benjamin.tissoires, peter.hutterer
Version:	unspecified
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	dmesg lsusb -v /proc/input/devices usb-devices

Description n.devaucleroy 2017-05-25 23:11:53 UTC

Created attachment 131517 [details]
dmesg

Honestly, it is not libinputs fault but the kernels. The kernel simply ignores the tackpad, which is listed in lsusb, but ignored at all other levels. I tried to force the usbhid driver to bind to it using echo -n "1-6" > /sys/bus/usb/drivers/usbhid/bind and other similar commands. I also managed to find the modalias of the usb device and tried to make it bind in etc/modprobe/local-aliases.conf :


alias usb:v06CBp0081d0164dcFFdsc10dpFFicFFisc00ip00in00 usbhid

I provided lsusb, dmesg, devices in the attachement. We can see that the kernel totally ignores the device for strange reasons. 

It is a bug common on all lenovo yoga 720 15", the 13" version doesn't have this problem. This laptop is expected to sell a lot because it is de facto the most powerfull convertible available on the market. 

https://forums.lenovo.com/t5/Linux-Discussion/Install-linux-in-Lenovo-Yoga-720/td-p/3633251

Comment 1 n.devaucleroy 2017-05-25 23:12:54 UTC

Created attachment 131518 [details]
lsusb -v

Comment 2 n.devaucleroy 2017-05-25 23:13:45 UTC

Created attachment 131519 [details]
/proc/input/devices

Comment 3 n.devaucleroy 2017-05-25 23:14:16 UTC

Created attachment 131520 [details]
usb-devices

Comment 4 arkng65 2017-06-23 21:40:23 UTC

I am completely new to this (no experience with patching/bugs), but this was posted on reddit and some other forums:
https://www.reddit.com/r/Lenovo/comments/6ebgbc/with_the_yoga_720_15_touchpad_not_working_on_linux/

It seems to follow the same line of reasoning of this patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v4.12-rc6&id=722c5ac708b4f5c1fcfad5fed4c95234c8b06590

Can this be checked?

Comment 5 Peter Hutterer 2017-06-26 23:57:54 UTC

CC-ing benjamin in case he's aware of it already. But I'd just give the proposed solution a try, rebuilding a kernel is relatively simple and there are a great many tutorials out there. Maybe start at kernelnewbies.org.

Otherwise I'll close this bug, it's not libinput and there isn't anything we can do in libinput to fix it, sorry. Please open this in the kernel bugzilla or raise it on the linux-input list.

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