Hi Krishna, On 6/24/24 7:09 AM, Krishna Kumar wrote: > Description of the problem: The hotplug driver for powerpc > (pci/hotplug/pnv_php.c) gives kernel crash when we try to > hot-unplug/disable the PCIe switch/bridge from the PHB. > > Root Cause of Crash: The crash is due to the reason that, though the msi > data structure has been released during disable/hot-unplug path and it > has been assigned with NULL, still during unregistartion the code was > again trying to explicitly disable the msi which causes the Null pointer > dereference and kernel crash. > > Proposed Fix : The fix is to correct the check during unregistration path > so that the code should not try to invoke pci_disable_msi/msix() if its > data structure is already freed. > > Cc: Michael Ellerman <m...@ellerman.id.au> > Cc: Nicholas Piggin <npig...@gmail.com> > Cc: Christophe Leroy <christophe.le...@csgroup.eu> > Cc: "Aneesh Kumar K.V" <aneesh.ku...@kernel.org> > Cc: Bjorn Helgaas <bhelg...@google.com> > Cc: Gaurav Batra <gba...@linux.ibm.com> > Cc: Nathan Lynch <nath...@linux.ibm.com> > Cc: Brian King <brk...@linux.vnet.ibm.com> > > Signed-off-by: Krishna Kumar <krish...@linux.ibm.com>
As with v1, I can confirm that this patch solves the panic encountered when hotplugging PCIe bridges on POWER9. Tested-by: Shawn Anastasio <sanasta...@raptorengineering.com> Thanks, Shawn
