https://bugs.freedesktop.org/show_bug.cgi?id=108997
Bug ID: 108997 Summary: RX460: Some Resolution-Refresh Combinations Unavailable when Connected via DisplayPort Product: DRI Version: unspecified Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: DRM/AMDgpu Assignee: dri-devel@lists.freedesktop.org Reporter: jeffbai@aosc.io
- Xorg Server version: 1.20.3 - XRandR version: 1.5.0 - Xf86-Video-AMDGPU version: 18.0.1 - Kernel parameters: root=UUID=dfd3d587-145e-4c01-af04-a3e24c59e95c rw quiet rw rd.auto rd.auto=1 splash vfio-pci.ids=10de:1c03,1022:145f,1022:1457 modprobe.blacklist=nouveau iommu=pt amd_iommu=on kvm-amd.avic=1 kvm-amd.nested=1 clocksource=tsc kvm.ignore_msrs=1 pcie_acs_override=multifunction rd.driver.pre=vfio-pci video=efifb:off
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Xorg.conf:
Section "Device" Identifier "Device 0" Driver "amdgpu" VendorName "Advanced Micro Devices, Inc." BusID "PCI:34:0:0" Option "IgnoreEDID" "true" Option "UseEDID" "false" EndSection
Section "Monitor" Identifier "Monitor 0" VendorName "SAMSUNG" ModelName "900SL" Option "UseEDID" "false" Option "UseEDIDFreqs" "false" Option "DDC" "false" HorizSync 30.0 - 96.0 VertRefresh 50.0 - 100.0 Modeline "1600x1200_76.00" 207.50 1600 1720 1888 2176 1200 1203 1207 1256 -hsync +vsync Option "PreferredMode" "1600x1200_76.00" EndSection
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While connecting my XFX Radeon RX460 Slim to a Samsung 900SL CRT monitor via a DisplayPort to VGA converter cable, 1600x1200@76Hz is not available, despite the factory specs...
1600 x 1200 / 76 Hz 1600 x 1200 / 70 Hz 1600 x 1200 / 65 Hz 1280 x 1024 / 89 Hz 1024 x 768 / 119 Hz 800 x 600 / 152 Hz 640 x 480 / 160 Hz
When attempting to create a new custom mode...
mingcongbai@NetVista [ / ] $ cvt 1600 1200 76 # 1600x1200 75.92 Hz (CVT) hsync: 95.36 kHz; pclk: 207.50 MHz Modeline "1600x1200_76.00" 207.50 1600 1720 1888 2176 1200 1203 1207 1256 -hsync +vsync
mingcongbai@NetVista [ / ] $ xrandr --newmode "1600x1200_76.00" 207.50 1600 1720 1888 2176 1200 1203 1207 1256 -hsync +vsync
mingcongbai@NetVista [ / ] $ xrandr --addmode DisplayPort-0 "1600x1200_76.00"
mingcongbai@NetVista [ / ] $ xrandr --output DisplayPort-0 --mode "1600x1200_76.00" xrandr: Configure crtc 0 failed
I have an NVIDIA GeForce GTX1060 passed through to a Windows 10 VM, connected via a DisplayPort to VGA, and VGA to BNC 5-pin connector, in this case, 1600x1200 is available and displays a correct image.
I have also tried to connect the RX460 with the DP-VGA-BNC cable, which yielded the same result.