@alexander-s-m: On a fresh install without any workarounds using VLC with the setting "Hardware-accelerated decoding" set to "VDPAU video decoder" (under Tools -> (Simple) Preferences -> Input/Codec) I experience the same low video quality on HDTV (H.264) video channels you are writing about. On UHD (H.265) channels the video is stuck.
Setting this to "disabled" in vlc gives good video quality on HD and UHD (the cpu is used intensively though). Oddly on Windows 10 this laptop (Lenovo Ideapad S540-14API) isn't able to show these HD or UHD tv channels without big glitches, no matter which settings, drivers or whatever. Reinstalling didn't help either. At least it seems to work good on Linux. Only other major issue with the laptop so far was the wifi card: Changing this to 01AX709 with an atheros chipset made wifi great again... But back to the topic: I suggest everyone who thinks to be affected by this issue to try to change one line in "/etc/default/grub" to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash iommu=soft" and run update-grub afterwards. This seems to have fixed the black screen issue so far (at least I haven't experienced the issue in the last 24 hours) and I didn't notice negative effects of this change. I'm running Ubuntu Mate 20.04 with 5.4.0-37-generic #41-Ubuntu SMP Wed Jun 3 18:57:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1870971 Title: [amdgpu] Xubuntu 20.04 boots to black screen on Lenovo Ideapad L340-17API To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1870971/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
