[Bug 196771] New: [AMDGPU] Scrambled video output during boot on WQHD monitor

[bugzilla-daemon at bugzilla.kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=196771

            Bug ID: 196771
           Summary: [AMDGPU] Scrambled video output during boot on WQHD
                    monitor
           Product: Drivers
           Version: 2.5
    Kernel Version: 4.12
          Hardware: x86-64
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Video(DRI - non Intel)
          Assignee: drivers_video-dri at kernel-bugs.osdl.org
          Reporter: rokups+kernel-bugs at zoho.com
        Regression: No

Created attachment 258103
  --> https://bugzilla.kernel.org/attachment.cgi?id=258103&action=edit
journalctl -b -1

When booting early KMS sets resolution somehow improperly. I attached example
of what it looks like. Appears that columns of pixels are skipped and other
visible columns are shifted left. Motherboard boot splashscreen and text of
bootloader (systemd-boot) are displayed properly, as soon as Xorg kicks in
everything is again displayed properly.

I also tried various combinations of video= and drm_kms_helper.edid_firmware=
boot parameters but nothing had any effect. This issue surfaced after getting
AMD card. Before i was using nvidia card with proprietary driver and this
monitor displayed boot text properly, although in low resolution. In attached
boot.log you can see logs of DMAR spam. When troubleshooting that i disabled
relevant features and DMAR no longer spewed any errors, however it did not
affect display of boot text output and it still was messed up. It also
prevented me from using VMs with passed-through GPU so that is why DMAR stuff
is enabled with all the error spam.

I have another 1080p monitor and it displays everything correctly on boot. It
is connected to AMD card through DVI cable.

Additional info:
* Distribution: Archlinux
* MSI Radeon™ RX 580 GAMING X 8G
* ASUS MG279Q 2560x1440 monitor connected through hdmi
* Opensource amdgpu driver
* early KMS ( MODULES="nls_iso8859-1 ext2 nls_cp437 nls_utf8 vfat cryptd
aes_x86_64 aesni_intel pci_stub vfio vfio_iommu_type1 vfio_pci vfio_virqfd kvm
kvm_intel amdgpu" )


03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc.
[AMD/ATI] Ellesmere [Radeon RX 470/480] [1002:67df] (rev e7) (prog-if 00 [VGA
controller])
Subsystem: Micro-Star International Co., Ltd. [MSI] Device [1462:3417]
Physical Slot: 6
Flags: bus master, fast devsel, latency 0, IRQ 31, NUMA node 0
Memory at c0000000 (64-bit, prefetchable) [size=256M]
Memory at d0000000 (64-bit, prefetchable) [size=2M]
I/O ports at e000 [size=256]
Memory at df100000 (32-bit, non-prefetchable) [size=256K]
Expansion ROM at 000c0000 [disabled] [size=128K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [58] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+


Steps to reproduce: happens always when booting with this combination of
hardware and amdgpu driver without any special setup. OpenSUSE tumbleweed and
Archlinux both have the problem.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.