Bug 198469

Summary:	When plugging in an external monitor using USB-C, sometimes a signal is reported
Product:	ACPI	Reporter:	Nico Schottelius (nico-bugzilla.kernel.org)
Component:	Power-Video	Assignee:	Zhang Rui (rui.zhang)
Status:	CLOSED MOVED
Severity:	normal	CC:	rui.zhang
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	4.14.12	Subsystem:
Regression:	No	Bisected commit-id:

Description Nico Schottelius 2018-01-13 20:58:17 UTC

I am connecting a Dell Latitude 5285 to a Samsung S27H850 by a USB-C cable (Hama USB 3.1, "full featured") and sometimes Xorg detects a signal, but loses it quickly again.

Connecting to the same monitor using an USB-C to display port adapter works.

When plugging the monitor in, in my recent kernel the following message is printed:

[217634.724851] usb 1-1: USB disconnect, device number 11
[217636.049722] acpi INT3400:00: Unsupported event [0x86]
[217674.130258] usb 1-3: new high-speed USB device number 12 using xhci_hcd
[217674.287390] hub 1-3:1.0: USB hub found
[217674.288923] hub 1-3:1.0: 4 ports detected
[217674.570263] usb 1-3.4: new full-speed USB device number 13 using xhci_hcd
[217674.685149] usb 1-3.4: not running at top speed; connect to a high speed hub
[217675.303530] acpi INT3400:00: Unsupported event [0x86]
[21:56] manager:~% 


Because of the ACPI message, I am reporting this against ACPI - if it belongs to the USB section, please let me know.

I tested the same cable & monitor with a Macbook, so the physical connection actually works fine.

My installed software versions are:


[21:56] manager:~% uname -r; pacman -Q | grep xorg
4.14.12-1-ARCH
xorg-appres 1.0.4-1
xorg-bdftopcf 1.1-1
xorg-font-util 1.3.1-1
xorg-font-utils 7.6-4
xorg-fonts-alias 1.0.3-1
xorg-fonts-encodings 1.0.4-4
xorg-fonts-misc 1.0.3-5
xorg-luit 1.1.1-2
xorg-mkfontdir 1.0.7-8
xorg-mkfontscale 1.1.2-1
xorg-server 1.19.6-2
xorg-server-common 1.19.6-2
xorg-server-xvfb 1.19.6-2
xorg-setxkbmap 1.3.1-1
xorg-xauth 1.0.10-1
xorg-xbacklight 1.2.1-1
xorg-xdpyinfo 1.3.2-1
xorg-xev 1.2.2-1
xorg-xinit 1.3.4-4
xorg-xinput 1.6.2-1
xorg-xkbcomp 1.4.0-1
xorg-xkill 1.0.4-1
xorg-xmodmap 1.0.9-1
xorg-xrandr 1.5.0-1
xorg-xrdb 1.1.0-2
xorg-xset 1.2.3-1
xorg-xwd 1.0.6-1
xorg-xwininfo 1.1.3-1
[21:56] manager:~%

Comment 1 Nico Schottelius 2018-01-14 13:47:12 UTC

After upgrading to 4.14.13-1-ARCH the screen turns on and stays on, until I suspend and turn the notebook on again.

After suspend, Linux shortly sees a signal, the image is seen on the external monitor and it turns off after a few seconds.

Funnily, leaving the screen connected, it turns off and on repeatedly (after about a minute it turns on and turns off after a few seconds.

While writing this bug report, characters I type are multipled (i.e. 12x n), when the screen is turning off or on.

Comment 2 Zhang Rui 2018-01-15 03:00:25 UTC

[217636.049722] acpi INT3400:00: Unsupported event [0x86]

this ACPI message is unrelated, plus it will be fixed after next merge window.

For the display issue, please file a bug at freedesktop.org instead.