Various regressions with amdgpu on Sea Island VGA (screen glitches and no HDMI)
Hello everyone. I use an HP 255 G5 laptop with a Radeon VGA belonging to Sea Island Family.
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Mullins [Radeon R3 Graphics] (rev 40)
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Kabini HDMI/DP Audio
Operating system is Arch Linux with latest linux
and linux-lts
kernels, version 5.13.13 and 5.10.60 respectively. DE is Gnome. I started using radeon drivers years ago, then switched to amdgpu for several reasons reported here.
I needed to use HDMI and one year ago @agd5f told me to enable Display Core since without it the audio was not outputting. Then the time has passed, I stayed on amdgpu with dc=1
and, at some time, I switched to lts kernel. The Stable Vanilla didn't give me particular issues, but I thought Long Term was better for my system so I used it (and without knowing I did the right choice).
In the last days I needed to use HDMI another time and sadly discovered that it's not working at all. It's not only audio, but also video is not showing. Later on I found out that the system is not even booting with amdgpu on stable kernel.
Then I tried all combinations of kernels, drivers and parameters in order to solve these regressions. Long story short, the state is the following:
-
amdgpu with Display Core on stable kernel
Not booting. Monitor is blank or, sometimes, is flickering at startup. No particular error lines are shown. The journal is similar to booting with LTS kernel. The only difference is that with LTS I can get into Gnome Desktop.
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amdgpu without Display Core on stable and LTS kernel
Same as one year ago for HDMI: no audio. But this time a new issue emerged. Some glitches appears occasionally on the screen, most of the time with the cursor. Some time I get a ghost cursor on the screen: the system is showing the old position of the cursor (maybe because that area is not refreshed). It's enough to update that area with a new window or passing on it with the cursor and the ghost cursor is gone.
Most of the time the ghost cursor is drawn partially, but less times it's even complete. It happens randomly, but I discovered that it's easily reproducible when a window is closed. In that situation the ghost cursor appears frequently.
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radeon driver on stable and LTS kernel
Same as one year ago: HDMI is fully working, but now ghost cursors are showing here also. The system keeps getting gpu freezes once in a while with this driver (I got one in about four days of testing and I'm pretty sure they will happen again if I keep using it).
For this reason it's not good for daily use. It's supposed to be stable since it's the designated driver for my card, but the truth is that it was stable three years ago, now amdgpu with dc is more reliable even if it's marked as "experimental" for Sea Island Family cards.
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amdgpu with Display Core on LTS kernel
It's the less problematic. Everything is working good, except HDMI. No freezes in more than a year. No screen glitches. No ghosts cursors. Very stable. Only issue is HDMI not working, which is clearly a regressions that I think it could be resolved because it was fully working one year ago.
One could say just use radeon for HDMI and amdgpu with Display Core for the rest, but it's not a solution and it's disappointing.
I hope these issues could be resolved, especially amdgpu on stable kernel because Arch won't ship 5.10 LTS eternally and with a new version I won't be able to use the card in a stable manner.