From 77bf04650069868e5ddaf2a0511c232395989191 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Fri, 17 Jun 2016 13:05:11 +1000 Subject: [PATCH] powerpc/eeh: Fix invalid cached PE primary bus commit a3aa256b7258b3d19f8b44557cc64525a993b941 upstream. The PE primary bus cannot be got from its child devices when having full hotplug in error recovery. The PE primary bus is cached, which is done in commit <05ba75f84864> ("powerpc/eeh: Fix stale cached primary bus"). In eeh_reset_device(), the flag (EEH_PE_PRI_BUS) is cleared before the PCI hot remove. eeh_pe_bus_get() then returns NULL as the PE primary bus in pnv_eeh_reset() and it crashes the kernel eventually. This fixes the issue by clearing the flag (EEH_PE_PRI_BUS) before the PCI hot add. With it, the PowerNV EEH reset backend (pnv_eeh_reset()) can get valid PE primary bus through eeh_pe_bus_get(). Fixes: 67086e32b564 ("powerpc/eeh: powerpc/eeh: Support error recovery for VF PE") Reported-by: Pridhiviraj Paidipeddi Signed-off-by: Gavin Shan Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/eeh_driver.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 31e4c7e1a4b4..c42627645b54 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -648,7 +648,6 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, if (pe->type & EEH_PE_VF) { eeh_pe_dev_traverse(pe, eeh_rmv_device, NULL); } else { - eeh_pe_state_clear(pe, EEH_PE_PRI_BUS); pci_lock_rescan_remove(); pcibios_remove_pci_devices(bus); pci_unlock_rescan_remove(); @@ -698,10 +697,12 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, */ edev = list_first_entry(&pe->edevs, struct eeh_dev, list); eeh_pe_traverse(pe, eeh_pe_detach_dev, NULL); - if (pe->type & EEH_PE_VF) + if (pe->type & EEH_PE_VF) { eeh_add_virt_device(edev, NULL); - else + } else { + eeh_pe_state_clear(pe, EEH_PE_PRI_BUS); pcibios_add_pci_devices(bus); + } } else if (frozen_bus && rmv_data->removed) { pr_info("EEH: Sleep 5s ahead of partial hotplug\n"); ssleep(5); -- 2.43.0