Bug 151331

Summary:	/dev/inpu/by-path links for PS/2 input devices are not created
Product:	Drivers	Reporter:	mutedbytes
Component:	Input Devices	Assignee:	drivers_input-devices
Status:	NEW ---
Severity:	normal	CC:	dmitry.torokhov, keithcu
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	4.7.0	Subsystem:
Regression:	No	Bisected commit-id:

Description mutedbytes 2016-08-03 06:06:02 UTC

It seems that with the update from 4.6.4 to 4.7.0 kernel, my system is no longer creating /dev/input/by-id and /dev/input/by-path links to i8042/PS/2 devices. Specifically, I previously was able to statically access my PS/2 keyboard through /dev/input/by-path/platform-i8042-serio-0-event-kbd which no longer exists/created with updated kernel. USB devices seem to be unchanged.

Comment 1 Keith Curtis 2016-08-24 00:34:49 UTC

I'm running 4.7.1 and also seeing this problem of no keyboard in my ../by-path directory (on a Yoga 2 Pro) which is breaking a userspace app. This seems like a regression. I was able to create a manual link (sudo ln -s ../event0 platform-event-kbd) so it was easy to work around.

Comment 2 Dmitry Torokhov 2016-08-24 18:25:53 UTC

dtor@dtor-glaptop:~/kernel/work$ uname -r
4.7.0+
dtor@dtor-glaptop:~/kernel/work$ ls -la /dev/input/by-path/
total 0
drwxr-xr-x 2 root root 200 Aug 24 09:17 .
drwxr-xr-x 4 root root 500 Aug 24 09:17 ..
lrwxrwxrwx 1 root root   9 Aug 23 09:30 pci-0000:00:14.0-usb-0:1.3.1:1.0-event-mouse -> ../event8
lrwxrwxrwx 1 root root   9 Aug 23 09:30 pci-0000:00:14.0-usb-0:1.3.1:1.0-mouse -> ../mouse1
lrwxrwxrwx 1 root root   9 Aug 23 09:30 pci-0000:00:14.0-usb-0:1.3.2:1.0-event-kbd -> ../event6
lrwxrwxrwx 1 root root   9 Aug 23 09:30 pci-0000:00:14.0-usb-0:1.3.2:1.1-event -> ../event7
lrwxrwxrwx 1 root root  10 Aug 24 09:17 pci-0000:00:14.0-usb-0:7:1.0-event -> ../event10
lrwxrwxrwx 1 root root   9 Aug 23 09:30 platform-i8042-serio-0-event-kbd -> ../event3
lrwxrwxrwx 1 root root   9 Aug 23 09:30 platform-i8042-serio-3-event-mouse -> ../event5
lrwxrwxrwx 1 root root   9 Aug 23 09:30 platform-i8042-serio-3-mouse -> ../mouse0

I'd start looking at your userspace (udev, systemd?) as well.

Comment 3 Keith Curtis 2016-08-24 20:17:57 UTC

Could it be possible that this problem only happens with some keyboards?

I don't know how to look into what udev and systemd are doing. I checked the systemd logs and didn't see anything suspicious.