Arch Linux

indeedwatson

Member

Registered: 2018-10-07

Posts: 28

Second monitor won't work with latest kernel

Not exactly sure how to troubleshoot this. In the past, I could make the 2nd monitor work by either using linux-lts or regular stable kernel with fallback initramfs. Today I boot up and fallback initramfs also has the issue, which is:

2nd monitor (DVI) is either completely black or has green vertical lines. I can move windows to it and whatnot but I cannot get an image.

Attempting to do something to it via xrandr locks up my whole computer.

It works perfectly fine with linux-lts so it's not a hardware issue.

Here are xorg logs https://paste.xinu.at/usaE/

These are my grub options:
GRUB_CMDLINE_LINUX_DEFAULT="threadirqs resume=/dev/mapper/MyVol-swap splash  amdgpu.si_support=1 radeon.si_support=0 nowatchdog rd.luks.options=discard"

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,120

Re: Second monitor won't work with latest kernel

That's not an xorg log, but a random list of modelines, all apparently gathered from the same type of monitor.
Please try "amdgpu.dc=0" and otherwise, post your full and unaltered dmesg and actual Xorg log: https://wiki.archlinux.org/index.php/Xorg#General

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indeedwatson

Member

Registered: 2018-10-07

Posts: 28

Re: Second monitor won't work with latest kernel

> That's not an xorg log, but a random list of modelines, all apparently gathered from the same type of monitor.

Sorry, I just pasted the last lines from ~/.local/share/xorg/Xorg.0.log, I thought the .log file *was* the log.

amdgpu.dc=0 seems to have worked, thank you, although now for some reason (and I assume unrelated), it won't automatically startx anymore, I have to ctrl + c in tty and startx manually.

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,120

Re: Second monitor won't work with latest kernel

Could be a timing issue (x starts before the GPU is initialized): https://wiki.archlinux.org/index.php/AM … _early_KMS
Also see the xorg logs.

Please always (unless asked) post complete logs, no excerpts or tails (context matters) - see the stickies in the newbie corner for best (aka "acceptable" ;-)  forum practices.

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

indeedwatson

Member

Registered: 2018-10-07

Posts: 28

Re: Second monitor won't work with latest kernel

I'm on latest kernel and once again getting green lines, even with amdgpu.dc=0

Here's the log https://paste.xinu.at/40QB/ and dmesg https://paste.xinu.at/qTp/

EDIT it also happens with -lts but it doesn't happen in latest kernel with fallback initramfs

These are my mkinitcpio hooks:
HOOKS=(base udev autodetect modconf block encrypt lvm2 filesystems keyboard keymap fsck)

Last edited by indeedwatson (2018-10-22 14:44:49)

seth

Member

From: Won't reply 2 private help req

Registered: 2012-09-03

Posts: 76,120

Re: Second monitor won't work with latest kernel

Did you check https://wiki.archlinux.org/index.php/AM … _early_KMS ?

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

indeedwatson

Member

Registered: 2018-10-07

Posts: 28

Re: Second monitor won't work with latest kernel

Yup, added amdgpu to the modules and rebuilt initramfs, 2nd monitor still not working. Gonna keep using fallback initramfs for now.

indeedwatson

Member

Registered: 2018-10-07

Posts: 28

Re: Second monitor won't work with latest kernel

No more ideas?

heisenberg

Member

Registered: 2017-05-27

Posts: 87

Re: Second monitor won't work with latest kernel

No more ideas?

Can you try with 4.17.14 kernel ?

indeedwatson

Member

Registered: 2018-10-07

Posts: 28

Re: Second monitor won't work with latest kernel

No more ideas?

Can you try with 4.17.14 kernel ?

Why that one specifically? Is there something about it that I can't test with lts?

heisenberg

Member

Registered: 2017-05-27

Posts: 87

Re: Second monitor won't work with latest kernel

No more ideas?

Can you try with 4.17.14 kernel ?

Why that one specifically? Is there something about it that I can't test with lts?

That's why https://bbs.archlinux.org/viewtopic.php?id=241212, it's easy to install from arch archives, check out the wiki. I think it's worth to give it a try.