@Martin: Thanks! As I suggested in the original bug description "radeon.agpmode=-1" works as boot option. But as it's a bug and I didn't find an up-to-date bug description I filed one. I am sure this affects some more users of Apple PPC hardware.
Interestingly enough my Powerbook 5,8 is not affected by this bug though it is equipped with a very similar r300-class graphics board! "ATI Radeon Mobility 9600/9700 (M10/M11) NP (AGP)", (ChipID = 0x4e50). ** Description changed: The freeze happens every time unless I use "radeon.agpmode=-1" as a - kernel parameter. Affected machine: PowerBook G4 5,6. + kernel parameter. + + Affected machines: + PowerBook G4 5,6 + PowerMac G5 7,3 (w. "ATI Radeon 9600 AP (AGP)". ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-18-powerpc-smp 4.4.0-18.34 ProcVersionSignature: Ubuntu 4.4.0-18.34-powerpc-smp 4.4.6 Uname: Linux 4.4.0-18-powerpc-smp ppc ApportVersion: 2.20.1-0ubuntu2 Architecture: powerpc AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CasperVersion: 1.373 CurrentDesktop: MATE Date: Sun Apr 17 21:08:40 2016 IwConfig: - lo no wireless extensions. - - enP2p36s15f0 no wireless extensions. + lo no wireless extensions. + + enP2p36s15f0 no wireless extensions. LiveMediaBuild: Ubuntu-MATE 16.04 LTS "Xenial Xerus" - Release powerpc (20160417.1) PccardctlIdent: - Socket 0: - no product info available + Socket 0: + no product info available PccardctlStatus: - Socket 0: - no card + Socket 0: + no card ProcEnviron: - TERM=xterm - PATH=(custom, no user) - XDG_RUNTIME_DIR=<set> - LANG=en_US.UTF-8 - SHELL=/bin/bash + TERM=xterm + PATH=(custom, no user) + XDG_RUNTIME_DIR=<set> + LANG=en_US.UTF-8 + SHELL=/bin/bash ProcFB: 0 radeondrmfb ProcKernelCmdLine: ro ramdisk_size=1048576 file=/cdrom/preseed/username.seed boot=casper quiet --- radeon.agpmode=-1 RelatedPackageVersions: - linux-restricted-modules-4.4.0-18-powerpc-smp N/A - linux-backports-modules-4.4.0-18-powerpc-smp N/A - linux-firmware 1.157 + linux-restricted-modules-4.4.0-18-powerpc-smp N/A + linux-backports-modules-4.4.0-18-powerpc-smp N/A + linux-firmware 1.157 RfKill: - 0: hci0: Bluetooth - Soft blocked: no - Hard blocked: no + 0: hci0: Bluetooth + Soft blocked: no + Hard blocked: no SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) -- 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/1571416 Title: System freezes shortly after reaching the desktop (Ubuntu MATE 16.04, PowerPC) Status in linux package in Ubuntu: Confirmed Bug description: The freeze happens every time unless I use "radeon.agpmode=-1" as a kernel parameter. Affected machines: PowerBook G4 5,6 + PowerMac G5 7,3 (w. "ATI Radeon 9600 AP (AGP)". ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-18-powerpc-smp 4.4.0-18.34 ProcVersionSignature: Ubuntu 4.4.0-18.34-powerpc-smp 4.4.6 Uname: Linux 4.4.0-18-powerpc-smp ppc ApportVersion: 2.20.1-0ubuntu2 Architecture: powerpc AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CasperVersion: 1.373 CurrentDesktop: MATE Date: Sun Apr 17 21:08:40 2016 IwConfig: lo no wireless extensions. enP2p36s15f0 no wireless extensions. LiveMediaBuild: Ubuntu-MATE 16.04 LTS "Xenial Xerus" - Release powerpc (20160417.1) PccardctlIdent: Socket 0: no product info available PccardctlStatus: Socket 0: no card ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 radeondrmfb ProcKernelCmdLine: ro ramdisk_size=1048576 file=/cdrom/preseed/username.seed boot=casper quiet --- radeon.agpmode=-1 RelatedPackageVersions: linux-restricted-modules-4.4.0-18-powerpc-smp N/A linux-backports-modules-4.4.0-18-powerpc-smp N/A linux-firmware 1.157 RfKill: 0: hci0: Bluetooth Soft blocked: no Hard blocked: no SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1571416/+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