Arch Linux

elkami

Member

Registered: 2016-05-11

Posts: 8

[SOLVED] black screen on the VGA output

Hi,

Few days ago, one of my external screens, connected through the VGA port, gone completely black (and after some tweaks, completely white, then black again...).
I log in from the CLI, the screen is black before X starts and stays black when X runs.

xrandr output is fine:

VGA-1 connected 1920x1080+4480+0 (normal left inverted right x axis y axis) 480mm x 270mm
   1920x1080     60.00*+
    ...

I did a system upgrade the last time the screen was working.

What I tried:
- Reverting some recent video related packages based on the output of 'ls -l /var/cache/pacman/pkg -t'
- Using the proprietary nvidia driver
- Installing and enabling bumblebee and bbswitch
- Setting 'nomodeset' in the grub config (X fails to start)

After each test, the issue remains so I restore the initial configuration (nouveau driver; nvidia, bumblebee and bbswitch removed; /etc/X11/ content removed).

I also tried running a live USB Linux: the screen worked as expected. The sorted

lsmod | grep nouveau

from the live Linux is:

drm                   drm_kms_helper,i915,ttm,nouveau
drm_kms_helper       i915,nouveau
i2c_algo_bit         i915,nouveau
mxm_wmi              nouveau
nouveau
ttm                  nouveau
video                msi_wmi,i915,nouveau
wmi                  msi_wmi,mxm_wmi,nouveau

My current system output is:

agpgart              intel_gtt,ttm,nouveau,drm
drm                   drm_kms_helper,i915,ttm,nouveau
drm_kms_helper       i915,nouveau
i2c_algo_bit         i915,nouveau
mxm_wmi              nouveau
nouveau
ttm                  nouveau
wmi                  msi_wmi,mxm_wmi,nouveau

The only diff is:

> agpgart              intel_gtt,ttm,nouveau,drm
< video                msi_wmi,i915,nouveau

Searching for 'video module' was not very helpful...

Did you experience something similar or do you have an idea on what is going wrong ?

My config: a laptop with an Intel® i7-4700HQ processor (Intel® HD Graphics 4600 integrated video chip) and a Nvidia GM107M [GeForce GTX 850M] GPU. The laptop screen (EDP1), an HDMI screen and a VGA screen.

'uname -a'

Linux bender 5.3.8-arch1-1 #1 SMP PREEMPT @1572357769 x86_64 GNU/Linux

Thanks

Last edited by elkami (2019-11-06 07:51:10)

chrisdb

Member

From: Belgium

Registered: 2018-05-16

Posts: 155

Re: [SOLVED] black screen on the VGA output

Please post output of:
- dmesg
- Xorg.0.log
- journal

And also

 lspci -v

thx

***EDIT
Did you also have a look at this:
https://wiki.archlinux.org/index.php/NV … grated_GPU

Last edited by chrisdb (2019-11-05 06:57:27)

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A.E.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,406

Re: [SOLVED] black screen on the VGA output

I agree with what you've requested, but it's highly unlikely that blacklisting intel modules will help here and it will likely in fact actually lead to no display at all working. One shouldn't follow these instructions on laptops were the integrated and separate cards have distinct but necessary functions.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 78,272

Re: [SOLVED] black screen on the VGA output

https://bbs.archlinux.org/viewtopic.php?id=250303

Esp. chck dmesg for "[drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable link training"

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elkami

Member

Registered: 2016-05-11

Posts: 8

Re: [SOLVED] black screen on the VGA output

Thank you for your answsers.

Indeed, I forgot to attach the dmesg output but it contained suspicious errors such as "[drm:hsw_fdi_link_train [i915]] *ERROR* FDI link training failed!" and nouveau 0000:01:00.0: bus: MMIO read of 00000000 FAULT at 022554 [ IBUS ])

I didn't think about looking at Xorg.0.log but again, very loud errors :

[    25.662] (WW) Warning, couldn't open module vesa
[    25.662] (EE) Failed to load module "vesa" (module does not exist, 0)
[    25.662] (II) intel: Driver for Intel(R) Integrated Graphics Chipsets:
	i810, i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G,
	915G, E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM,
	Pineview G, 965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33,
	GM45, 4 Series, G45/G43, Q45/Q43, G41, B43
[    25.662] (II) intel: Driver for Intel(R) HD Graphics
[    25.662] (II) intel: Driver for Intel(R) Iris(TM) Graphics
[    25.662] (II) intel: Driver for Intel(R) Iris(TM) Pro Graphics
[    25.662] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[    27.683] intel: waited 2020 ms for i915.ko driver to load
[    27.686] (EE) open /dev/dri/card0: No such file or directory
[    27.686] (WW) Falling back to old probe method for modesetting
[    27.686] (EE) open /dev/dri/card0: No such file or directory
[    27.686] (EE) Screen 0 deleted because of no matching config section.
[    27.686] (II) UnloadModule: "modesetting"
[    27.686] (EE) Device(s) detected, but none match those in the config file.

Downgrading linux to 5.2.14.arch1-1 did the trick.

thank you.