VEGA 64 config for 1680x1050 is incorrect

[Philip Pokorny]

I have two AMD GPU cards in my system connected to an identical pair of older SAMSUNG monitors with native resolution of 1680x1050.

$ lspci -d ::300
0a:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Vega 10 XT [Radeon RX Vega 64] (rev c1)
42:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV770 [Radeon HD 4850]

The RV770 has successfully been connected to these two monitors for many years.

Recently upgraded the motherboard and added the Vega 64 video card.

Connecting DisplayPort from the Vega 64 to one monitor and the RV770 to the other, The Vega 64 monitor display is corrupted. See attached picture.

I tried all the other supported modes for the monitor and the others all work fine (1024x768, 1280x1024, etc.) Although, it is perhaps interesting that 1680x1050 is the only 1.6:1 aspect ratio. The majority are 4:3 with 1280x1024 (5:4) and 720x400 (9:5) the exceptions. And all the other modes seem to display in a 4:3 subset of the pixels on the screen.

I'll upload the /var/log/Xorg.0.log next.

Other info:
$ lsb_release -rd
Description: Linux Mint 19.1 Tessa
Release: 19.1

$ apt-cache policy xserver-xorg-video-amdgpu
xserver-xorg-video-amdgpu:
  Installed: 18.0.1-1
  Candidate: 18.0.1-1
  Version table:
 *** 18.0.1-1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

EXPECTATION: Correct display output

ACTUAL RESULT: "Torn" display.
---
ProblemType: Bug
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC1D0p: philip 2211 F...m pulseaudio
 /dev/snd/controlC1: philip 2211 F.... pulseaudio
 /dev/snd/controlC0: philip 2211 F.... pulseaudio
 /dev/snd/controlC2: philip 2211 F.... pulseaudio
CurrentDesktop: X-Cinnamon
DistroRelease: Linux Mint 19.1
InstallationDate: Installed on 2019-03-10 (0 days ago)
InstallationMedia: Linux Mint 19.1 "Tessa" - Release amd64 20181217
IwConfig:
 lo no wireless extensions.

 enp4s0 no wireless extensions.
MachineType: Gigabyte Technology Co., Ltd. X399 AORUS PRO
Package: linux (not installed)
ProcFB:
 0 radeondrmfb
 1 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.15.0-46-generic root=UUID=14bde5f7-3295-4e41-bc36-8d22c00349f9 ro rootflags=subvol=@ quiet splash vt.handoff=1
ProcVersionSignature: Ubuntu 4.15.0-46.49-generic 4.15.18
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-46-generic N/A
 linux-backports-modules-4.15.0-46-generic N/A
 linux-firmware 1.173.3
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
Tags: tessa
Uname: Linux 4.15.0-46-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 10/01/2018
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F1
dmi.board.asset.tag: Default string
dmi.board.name: X399 AORUS PRO-CF
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF1:bd10/01/2018:svnGigabyteTechnologyCo.,Ltd.:pnX399AORUSPRO:pvrDefaultstring:rvnGigabyteTechnologyCo.,Ltd.:rnX399AORUSPRO-CF:rvrx.x:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: Default string
dmi.product.name: X399 AORUS PRO
dmi.product.version: Default string
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Philip Pokorny (ppokorny)]

My Xorg.0.log including logs of me switching modes many times.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1819383

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Philip Pokorny (ppokorny)]

apport information

[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

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[Philip Pokorny (ppokorny)]

I don't think this is a kernel issue. More likely Xorg

[Philip Pokorny (ppokorny)]

Actually, the Vega 64 uses the radeon driver

$ apt-cache policy xserver-xorg-video-radeon
xserver-xorg-video-radeon:
  Installed: 1:18.0.1-1
  Candidate: 1:18.0.1-1
  Version table:
 *** 1:18.0.1-1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

[Philip Pokorny (ppokorny)]

$ apt-cache policy xserver-xorg-video-radeon
xserver-xorg-video-radeon:
  Installed: 1:18.0.1-1
  Candidate: 1:18.0.1-1
  Version table:
 *** 1:18.0.1-1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

[Philip Pokorny (ppokorny)]

No. I was right the first time

[Kai-Heng Feng (kaihengfeng)]

I guess it's still related to the kernel:
[ 3.674022] [drm] {1680x1050, 1840x1080@119000Khz}

[Kai-Heng Feng (kaihengfeng)]

Would it be possible for you to test the latest upstream kernel? Refer
to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest
v5.0 kernel [0].

If this bug is fixed in the mainline kernel, please add the following
tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag:
'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as
"Confirmed”, and attach dmesg.

Thanks in advance.

[0] https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/

[Philip Pokorny (ppokorny)]

I tried the latest v5.0.3 kernel and it has the same behaviour.

I notice that the drm output happened before but not recently. And the different sizes seem normal as the 3840x2160 main HD monitor that's new says something similar but it works fine:

kernel: [ 187.417408] [drm] {3840x2160, 4000x2222@533120Khz}

I'll add the "kernel-bug-exists-upstream" tag, mark it confirmed and attached dmesg output. But the DRM module no longer logs the screen resolutions...