Bug 111322 - Loss of multi-display support when using USB-C Travel Hub after suspend.
Summary: Loss of multi-display support when using USB-C Travel Hub after suspend.
Status: NEEDINFO
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard: Triaged
Keywords:
Depends on:
Blocks:
 
Reported: 2019-08-08 03:52 UTC by Steven Ellis
Modified: 2019-11-07 22:11 UTC (History)
1 user (show)

See Also:
i915 platform: KBL
i915 features: display/USB-C


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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.


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