RDNA2 Navi22/23 [and RNDA?] - AMDGPU display out non-functional on riscv [SiFive HiFive Unmatched]
Issue:
No display output [HDMI & DP] on RDNA2 cards on riscv.
RDNA2 - Radeon RX 6600 and 6700 XT - gfx cards appear to be initialised correctly [no errors shown in dmesg or boot log], and lspci
and vainfo
run correctly after [ssh or serial] terminal login, but nothing is ever displayed [over HDMI or DP].
Reports for 6600 detailed / attached. RX 6700 XT reports are pretty much identical...and can be supplied if necessary.
This exact system - including monitor and DP and HDMI cables - works perfectly with RX 550 [4GB] and RX 580 [8GB] gfx cards. [I haven't tried an RDNA1 or Vega card, but have access to them if needed...].
This YouTube video by Rene Rebe(https://www.youtube.com/watch?v=Sv4-_a_3BKg) [from July 18th] suggests it is an issue that can be hacked around [he shows a working system with a 6700 XT that took "6 hours of hacking"]. However, he hasn't shared the details publicly, and he insinuates that the non-functional display-output [on non-x86 hardware] may have a known root cause, and even be intentional(?)...
dmesg-output-rx6600-01-20211017.txt
unmatched-bootlog-rx6600-20211017.txt
vaainfo-rx6600-01-20211017.txt
Hardware description:
- CPU: SiFive Freedom U740
- GPU:
09:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 23 [Radeon RX 6600/6600 XT/6600M] [1002:73ff] (rev c7)
09:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 HDMI Audio [Radeon RX 6800/6800 XT / 6900 XT] [1002:ab28]
- System Memory: 16 GB
- Display(s): Dell U2143 [& others]
- Type of Display Connection: DP & HDMI
System information:
- Ubuntu 21.10
- Kernel version:
Linux ubuntu 5.13.0-1004-generic #4-Ubuntu SMP Thu Sep 30 05:02:57 UTC 2021 riscv64 riscv64 riscv64 GNU/Linux
Mesa Gallium driver 21.2.2 for AMD DIMGREY_CAVEFISH (DRM 3.41.0, 5.13.0-1004-generic, LLVM 12.0.1)
How to reproduce the issue:
To reproduce... simply attach RDNA2 gfx card to PCIE slot and boot - serial terminal boot output, lspci, vainfo and dmesg logs all attached...-