I think I fixed the problem by improving the slot_no_hotplug function in /drivers/pci/hotplug/acpiphp_glue.c
As far as I can tell the radeon driver set the ignore_hotplug on my radeon pci device, but the slot_no_hotplug function never got deep enough to reach the pci device with this flag. After I added the functionality to iterate through all the subordinate pci devices, the function got to the flag and didn't remove my radeon device after it was powered down by the radeon driver (which is the expected behaviour). ** Patch added: "0001-Fixed-a-slot_no_hotplug-bug-in-acpiphp-system.patch" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1414789/+attachment/4324947/+files/0001-Fixed-a-slot_no_hotplug-bug-in-acpiphp-system.patch -- 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/1414789 Title: Kernel Oops - unable to handle kernel NULL pointer dereference at 0000000000000010; EIP is at fb_release+0x26/0x60 Status in linux package in Ubuntu: Confirmed Bug description: My laptop has a kernel problem with the Ubuntu 15.04 live disk. The Kernel reports constantly about a NULL pointer reference. Sometimes the X-server starts without the Unity interface and the UI freezes constantly for a few seconds. It often ends with a complete freeze of the computer. Other times the computer freezes before the desktop was loaded. I think it could be the radeon driver for my ATI Mobility Radeon HD 5650. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: linux-image-3.18.0-9-generic 3.18.0-9.10 ProcVersionSignature: Ubuntu 3.18.0-9.10-generic 3.18.2 Uname: Linux 3.18.0-9-generic x86_64 ApportVersion: 2.15.1-0ubuntu2 Architecture: amd64 AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D1p', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/controlC0', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CasperVersion: 1.349 Date: Mon Jan 26 21:52:58 2015 LiveMediaBuild: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150126) ProcEnviron: TERM=linux PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: noprompt cdrom-detect/try-usb=true persistent file=/cdrom/preseed/username.seed boot=casper initrd=/casper/initrd.lz quiet splash -- BOOT_IMAGE=/casper/vmlinuz.efi PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-3.18.0-9-generic N/A linux-backports-modules-3.18.0-9-generic N/A linux-firmware 1.141 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 03/16/2011 dmi.bios.vendor: INSYDE dmi.bios.version: V1.25 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: JM41_CP dmi.board.vendor: Acer dmi.board.version: Base Board Version dmi.chassis.type: 10 dmi.chassis.vendor: Chassis Manufacturer dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnINSYDE:bvrV1.25:bd03/16/2011:svnAcer:pn:pvrV1.25:rvnAcer:rnJM41_CP:rvrBaseBoardVersion:cvnChassisManufacturer:ct10:cvrChassisVersion: dmi.product.version: V1.25 dmi.sys.vendor: Acer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1414789/+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
