From a3aa256b7258b3d19f8b44557cc64525a993b941 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 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 --- 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 2714a3b81d24..b5f73cb5eeb6 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -642,7 +642,6 @@ 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(); pci_hp_remove_devices(bus); pci_unlock_rescan_remove(); @@ -692,10 +691,12 @@ 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); pci_hp_add_devices(bus); + } } else if (frozen_bus && rmv_data->removed) { pr_info("EEH: Sleep 5s ahead of partial hotplug\n"); ssleep(5); -- 2.20.1