From 29bf282dec94f6015a675c007614cb29563f1c18 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Tue, 6 Sep 2016 16:34:01 +1000 Subject: [PATCH] powerpc/powernv: Detach from PE on releasing PCI device The PCI hotplug can be part of EEH error recovery. The @pdn and the device's PE number aren't removed and added afterwords. The PE number in @pdn should be set to an invalid one. Otherwise, the PE's device count is decreased on removing devices while failing to be increased on adding devices. It leads to unbalanced PE's device count and make normal PCI hotplug path broken. Fixes: c5f7700bbd2e ("powerpc/powernv: Dynamically release PE") Signed-off-by: Gavin Shan Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/pci-ioda.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 0c71a2f..da5da11 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -3452,7 +3452,17 @@ static void pnv_pci_release_device(struct pci_dev *pdev) if (!pdn || pdn->pe_number == IODA_INVALID_PE) return; + /* + * PCI hotplug can happen as part of EEH error recovery. The @pdn + * isn't removed and added afterwards in this scenario. We should + * set the PE number in @pdn to an invalid one. Otherwise, the PE's + * device count is decreased on removing devices while failing to + * be increased on adding devices. It leads to unbalanced PE's device + * count and eventually make normal PCI hotplug path broken. + */ pe = &phb->ioda.pe_array[pdn->pe_number]; + pdn->pe_number = IODA_INVALID_PE; + WARN_ON(--pe->device_count < 0); if (pe->device_count == 0) pnv_ioda_release_pe(pe); -- 2.7.4