This is a note to let you know that I've just added the patch titled powerpc/pseries: extract host bridge from pci_bus prior to bus removal to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-pseries-extract-host-bridge-from-pci_bus-pri.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c027e859eca714a73b27fb26b6ba81888c9051cb Author: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx> Date: Thu Feb 11 12:24:35 2021 -0600 powerpc/pseries: extract host bridge from pci_bus prior to bus removal [ Upstream commit 38d0b1c9cec71e6d0f3bddef0bbce41d05a3e796 ] The pci_bus->bridge reference may no longer be valid after pci_bus_remove() resulting in passing a bad value to device_unregister() for the associated bridge device. Store the host_bridge reference in a separate variable prior to pci_bus_remove(). Fixes: 7340056567e3 ("powerpc/pci: Reorder pci bus/bridge unregistration during PHB removal") Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210211182435.47968-1-tyreld@xxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c index 5d4a3df59d0c..baaeb753fa79 100644 --- a/arch/powerpc/platforms/pseries/pci_dlpar.c +++ b/arch/powerpc/platforms/pseries/pci_dlpar.c @@ -98,6 +98,7 @@ EXPORT_SYMBOL_GPL(init_phb_dynamic); int remove_phb_dynamic(struct pci_controller *phb) { struct pci_bus *b = phb->bus; + struct pci_host_bridge *host_bridge = to_pci_host_bridge(b->bridge); struct resource *res; int rc, i; @@ -124,7 +125,8 @@ int remove_phb_dynamic(struct pci_controller *phb) /* Remove the PCI bus and unregister the bridge device from sysfs */ phb->bus = NULL; pci_remove_bus(b); - device_unregister(b->bridge); + host_bridge->bus = NULL; + device_unregister(&host_bridge->dev); /* Now release the IO resource */ if (res->flags & IORESOURCE_IO)