Bug 111322

Summary:	Loss of multi-display support when using USB-C Travel Hub after suspend.
Product:	DRI	Reporter:	Steven Ellis <sellis>
Component:	DRM/Intel	Assignee:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Status:	RESOLVED MOVED	QA Contact:	Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity:	normal
Priority:	medium	CC:	intel-gfx-bugs
Version:	XOrg git
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:	Triaged
i915 platform:	KBL	i915 features:	display/USB-C

Description Steven Ellis 2019-08-08 03:52:19 UTC

Hardware
 - Lenovo T480s
 - Lenovo USB-C Travel Hub
 - Dell 24" Monitor

OS
 - Fedora 29
 - xorg-x11-drv-intel-2.99.917-42.20180618.fc29.x86_64
 - Kernel 5.1.20-200.fc29.x86_64

I have a HDMI monitor, USB keyboard/mouse and network cable connected to the Lenovo USB-C travel hub at home.

Sometime when I connect this after the laptop has been suspended I get the following errors in the system log, and dual monitor support no longer works.

Aug 08 09:56:47 t480s kernel: [drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable link training
Aug 08 09:56:47 t480s kernel: [drm:intel_mst_pre_enable_dp [i915]] *ERROR* failed to allocate vcpi
Aug 08 09:56:47 t480s kernel: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
Aug 08 09:56:47 t480s kernel: [drm:intel_mst_pre_enable_dp [i915]] *ERROR* failed to allocate vcpi

Once I've seen this error I can only run a single display 
 - Joined displays don't work
 - Mirroring doesn't work

I'm still running Xorg due to some other Wayland issues and I can see the following in my logs when I try and enable my normal joined display

Aug 08 11:24:31 t480s /usr/libexec/gdm-x-session[2657]: (II) modeset(0): Allocate new frame buffer 3840x1200 stride
Aug 08 11:24:31 t480s /usr/libexec/gdm-x-session[2657]: (EE) modeset(0): failed to set mode: Invalid argument

Currently my only fix is to reboot the system.

Comment 1 Steven Ellis 2019-08-08 03:52:53 UTC

This may relate to the following other BZs

https://bugzilla.redhat.com/show_bug.cgi?id=1667000
https://bugs.freedesktop.org/show_bug.cgi?id=109522

Comment 2 Lakshmi 2019-08-08 06:23:39 UTC

Reporter, please try to reproduce this issue using drm-tip (https://cgit.freedesktop.org/drm-tip) with kernel parameters drm.debug=0x1e log_buf_len=4M. If the problem persists attach the full dmesg from boot.

Comment 3 Lakshmi 2019-10-02 12:41:09 UTC

No updates for more than a month.
@Steven, Did you get any time to verify the issue with drmtip?

Comment 4 Steven Ellis 2019-11-07 22:11:46 UTC

Sorry I hadn't seen the response. I haven't had an opportunity to try drm-tip

I'll try to take a look at it in a couple of weeks as I'm currently travelling and don't have access to the docks.

Comment 5 Martin Peres 2019-11-29 19:22:19 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/drm/intel/issues/360.

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