From 527d10ef3a315d3cb9dc098dacd61889a6c26439 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 8 Oct 2015 14:58:52 +1100 Subject: [PATCH] powerpc/eeh: Don't unfreeze PHB PE after reset On PowerNV platform, the PE is kept in frozen state until the PE reset is completed to avoid recursive EEH error caused by MMIO access during the period of EEH reset. The PE's frozen state is cleared after BARs of PCI device included in the PE are restored and enabled. However, we needn't clear the frozen state for PHB PE explicitly at this point as there is no real PE for PHB PE. As the PHB PE is always binding with PE#0, we actually clear PE#0, which is wrong. It doesn't incur any problem though. This checks if the PE is PHB PE and doesn't clear the frozen state if it is. Signed-off-by: Gavin Shan Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/eeh_driver.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 89eb4bc34d3a..3a626edbb319 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -587,10 +587,16 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus) eeh_ops->configure_bridge(pe); eeh_pe_restore_bars(pe); - /* Clear frozen state */ - rc = eeh_clear_pe_frozen_state(pe, false); - if (rc) - return rc; + /* + * If it's PHB PE, the frozen state on all available PEs should have + * been cleared by the PHB reset. Otherwise, we unfreeze the PE and its + * child PEs because they might be in frozen state. + */ + if (!(pe->type & EEH_PE_PHB)) { + rc = eeh_clear_pe_frozen_state(pe, false); + if (rc) + return rc; + } /* Give the system 5 seconds to finish running the user-space * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,