Before bisecting, I investigated the PCI issue: https://bugs.launchpad.net/bugs/1902795
I've faced the PCI issue before the AGP one, but it was less critical. I've submitted a patch that may fix some issues (with drawback of being non-optimal on platforms were PCI graphics are known to already work) but not everything is fixed. To be clear: that does not fix PCI GPU failure on K8 / K10 neither AGP-as-PCI failure, but that is at least a step forward, and would help specialists to investigate more the issue. At this point I may have reached my skill cap on such topic. Because PCI and AGP-as-PCI behaves differently and the later code may have specific bugs, I opened an issue dedicated to track bugs when AGP cards are driven as PCI ones: https://bugs.launchpad.net/bugs/1902981 I did not bisected anything after having identified the breakage was introduced by 5.9-rc1, and I directly tried to revert commit ba806f98f868ce107aa9c453fef751de9980e4af that disabled AGP at kernel build. I reverted this commit over the 5.10-rc2 tag from the torvalds branch and both the ATI Radeon HD 4670 on the K10 computer and the ATI Radeon X1950 PRO on the AMD K8 computer started to work again immediately. Game performance was as expected and desktop experience was really smooth like we can expect from such aging but high end hardware from its time. It looks like I misread your first comment, I believed you were asking me to try the 5.10-rc1 build like if that commit was already reverted (the only action that seems to be able to fix the issue at this point). After this commit is reverted, I have not yet noticed the other issues I've reported (disk IO seems to be OK, I have not tested audio yet), so the other ones may have been collateral damage of the AGP/PCI one. So, you were right, the regression was introduced by the "drm/radeon: disable AGP by default" commit. It sounds too early to disable without alternative some hardware that was still sold as brand new in 2012 (the ATI Radeon HD 4670 AGP was). -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1899304 Title: AGP disablement leaves GPUs without working alternative (PCI fallback is broken), makes very-capable ATI TeraScale GPUs unusable Status in linux package in Ubuntu: Confirmed Bug description: This system runs Ubuntu 20.04, freshly installed 3~4 months ago (July 2020). There is two kernels available on this system: - 5.4.0-47-generic - 5.4.0-48-generic With kernel 5.4.0-47-generic: - GNOME shell loads properly on Radeon X1950 PRO, - Unvanquished game runs on ATI Radeon X1950 PRO at 70 fps on 1280×720 resolution, - Unvanquished game runs on ATI Radeon 9500 at 40 fps on 640×480 resolution. Everything looks consistent with the limits and the age of the hardware. With kernel 5.4.0-48-generic: - GNOME Shell never finish to load on Radeon X1950 PRO, either a grey screen is displayed and keyboard shortcuts does not respond, or the top bar is stuck between the center and the top of the screen and the shell does not respond, or the top bar on the top of the screen but the shell does not respond, to get a desktop I run `sudo systemctl stop display-manager` then `startx /usr/bin/lxsession` from a TTY. Running GNOME Shell with startx or from a lone xterm started with startx leads to same issues. - Unvanquished game runs on ATI Radeon X1950 PRO at 7 fps on 1280×720 resolution, - Unvanquished game runs on ATI Radeon 9500 at 3 fps on 640×480 resolution. Note: for unknown reasons, GNOME Shell loads properly on the ATI Radeon 9500 but not on the Radeon X1950 PRO. Everything is slow. When the game is running, a very high load is reported by htop, which does not look like the experience seen on the 5.4.0-47-generic kernel. When the game is running cycling between windows using Alt-Tab takes a lot of second while it's immediate on 5.4.0-47-generic kernel. Also, even without the game running or on a lightweight desktop like LXDE, cycling windows is not smooth and window refreshing is slow enough to be noticeable. About the hardware, note that: - the CPU only has one core, no hyperthreading (AMD Athlon 64 FX for socket 939), - the GPUs are AGP ones using R300 and R500 technology (pre-TeraScale), - there is 3GB of DDR RAM, - there is no on-disk swap but zram-based swap in compressed ram is used, - system is stored on and boots from an USB 3.1 key plugged on an USB 2.0 port, - /tmp is a tmpfs ram disk, - CPU is set to performance profile, - the install is not really messy and not many packages are installed, this USB key is purposed for hardware/system testing and to diagnose such issues. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-48-generic 5.4.0-48.52 ProcVersionSignature: Ubuntu 5.4.0-48.52-generic 5.4.60 Uname: Linux 5.4.0-48-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.9 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: illwieckz 7503 F.... pulseaudio CasperMD5CheckResult: skip Date: Sun Oct 11 01:47:48 2020 InstallationDate: Installed on 2020-07-09 (93 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) IwConfig: enp0s11 no wireless extensions. lo no wireless extensions. MachineType: MSI MS-6702E ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=fr_FR.UTF-8 SHELL=/bin/bash ProcFB: 0 radeondrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-48-generic root=UUID=10314d0c-ec6b-4f7f-b926-ed8b80185331 ro PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-5.4.0-48-generic N/A linux-backports-modules-5.4.0-48-generic N/A linux-firmware 1.187.3 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 10/12/2006 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 080011 dmi.board.asset.tag: To Be Filled By O.E.M. dmi.board.name: MS-6702E dmi.board.vendor: MSI dmi.board.version: 1.0 dmi.chassis.asset.tag: To Be Filled By O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: To Be Filled By O.E.M. dmi.chassis.version: To Be Filled By O.E.M. dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr080011:bd10/12/2006:svnMSI:pnMS-6702E:pvr1.0:rvnMSI:rnMS-6702E:rvr1.0:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.: dmi.product.family: To Be Filled By O.E.M. dmi.product.name: MS-6702E dmi.product.sku: To Be Filled By O.E.M. dmi.product.version: 1.0 dmi.sys.vendor: MSI To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1899304/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp