Arch Linux

Delta07

Member

Registered: 2018-09-23

Posts: 4

[GPU - Radeon - Black Screen] black screen if i don't have nomodeset

Hi guys

Obviously i'm a newbie, and i switch to Arch because it's time to me to become better with linux.

I tried to install correctly my Arch by following the wiki install, and that's pretty.
But since the first reboot, i'am not able to access the prompt login without adding "nomodeset" to the grub command.
so I tried to install drivers for my ATI R9 380 following the wiki page about ATI. It's not working.

From this part, i'm lost. I don't understand how the kernel works for modules, especially for gpu, so i have no idea from where i should start my research.
And to be honest, i made some research, but there are so many post that tell you "put this here" "type the line" "add this variable" and so many conf file. A don't want to just try all (a did some, and it's not working) without understand my problem.

The 2 messages i got and i don't understand are :

At the loging prompt

error vgacon disables amdgpu kernel modesetting

with a dmesg | grep radeon

*ERROR* No UMS support in radeon module

So i have2 questions:

- Does anyone have an idea for my black screen and/or for my radeon not working ?
- Where i can start learning a bit about module kernel and understand wtf?

Thanks guys, and sorry for the bad english.

loqs

Member

Registered: 2014-03-06

Posts: 19,113

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

Welcome to the arch linux forums Delta07.  Please post the kernel messages from a boot with the nomodeset option and without nomodeset option
eg

journalctl -b 0 -k # if the current boot was with modeset
journalctl -b -1 -k #if the last boot was without modeset

Delta07

Member

Registered: 2018-09-23

Posts: 4

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

Thanks for reply.

There are about 800 lines, and it's on a PC where a could not make a screen or copy paste. Do you have some precision in the command ?

By the way, with nomodeset I have 2 red lines and it's the same messages I talked about in my first message.

And without the nomodeset option, I just have a black screen. I can't do nothing.

loqs

Member

Registered: 2014-03-06

Posts: 19,113

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

List_of_applications#Pastebin_clients assuming the system has network access that should allow you to post the output from the console.

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 15,552

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

You can probably avoid getting the black screen by booting to multi-user target instead of (the default) graphical target.

See https://wiki.archlinux.org/index.php/Sy … _boot_into

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

Delta07

Member

Registered: 2018-09-23

Posts: 4

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

Hi

THis is the commande

 journalctl -b -1 -k

with a nomodeset at the start
https://pastebin.com/zHFtcDmU

Unfortunaly booting with multi-user give me a black screet again.

loqs

Member

Registered: 2014-03-06

Posts: 19,113

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

sept. 25 21:29:27 fixeCharly kernel: [drm] dce110_link_encoder_construct: Failed to get encoder_cap_info from VBIOS with error code 4!
sept. 25 21:29:27 fixeCharly kernel: [drm] dce110_link_encoder_construct: Failed to get encoder_cap_info from VBIOS with error code 4!
sept. 25 21:29:27 fixeCharly kernel: [drm] dce110_link_encoder_construct: Failed to get encoder_cap_info from VBIOS with error code 4!
sept. 25 21:29:27 fixeCharly kernel: [drm] Display Core initialized with v3.1.44!
sept. 25 21:29:27 fixeCharly kernel: [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
sept. 25 21:29:27 fixeCharly kernel: [drm] Driver supports precise vblank timestamp query.
sept. 25 21:29:27 fixeCharly kernel: [drm] UVD initialized successfully.
sept. 25 21:29:27 fixeCharly kernel: [drm] VCE initialized successfully.
sept. 25 21:29:27 fixeCharly kernel: [drm] Cannot find any crtc or sizes

Please try the boot option amdgpu.dc=0 (without nomodeset) and post updated kernel messages if that does not resolve the issue.

Delta07

Member

Registered: 2018-09-23

Posts: 4

Re: [GPU - Radeon - Black Screen] black screen if i don't have nomodeset

Hi loqs.

It seems to be working.The resolution of my tty is now correct.,

So big thx, you saved me. I don't understand DC amdgpu for the moment. I will read more about it

I guess the next step is to set the amdgpu.dc=0 at the boot, i will make some search about this too.
Anything else i had to know ?