This is a note to let you know that I've just added the patch titled powerpc/eeh: Fix fenced PHB caused by eeh_slot_error_detail() to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-eeh-fix-fenced-phb-caused-by-eeh_slot_error_detail.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 259800135c654a098d9f0adfdd3d1f20eef1f231 Mon Sep 17 00:00:00 2001 From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Date: Fri, 28 Aug 2015 11:57:00 +1000 Subject: powerpc/eeh: Fix fenced PHB caused by eeh_slot_error_detail() From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> commit 259800135c654a098d9f0adfdd3d1f20eef1f231 upstream. The config space of some PCI devices can't be accessed when their PEs are in frozen state. Otherwise, fenced PHB might be seen. Those PEs are identified with flag EEH_PE_CFG_RESTRICTED, meaing EEH_PE_CFG_BLOCKED is set automatically when the PE is put to frozen state (EEH_PE_ISOLATED). eeh_slot_error_detail() restores PCI device BARs with eeh_pe_restore_bars(), which then calls eeh_ops->restore_config() to reinitialize the PCI device in (OPAL) firmware. eeh_ops->restore_config() produces PCI config access that causes fenced PHB. The problem was reported on below adapter: 0001:01:00.0 0200: 14e4:168e (rev 10) 0001:01:00.0 Ethernet controller: Broadcom Corporation \ NetXtreme II BCM57810 10 Gigabit Ethernet (rev 10) This fixes the issue by skipping eeh_pe_restore_bars() in eeh_slot_error_detail() when EEH_PE_CFG_BLOCKED is set for the PE. Fixes: b6541db1 ("powerpc/eeh: Block PCI config access upon frozen PE") Reported-by: Manvanthara B. Puttashankar <mputtash@xxxxxxxxxx> Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/kernel/eeh.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -310,11 +310,26 @@ void eeh_slot_error_detail(struct eeh_pe if (!(pe->type & EEH_PE_PHB)) { if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG)) eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + + /* + * The config space of some PCI devices can't be accessed + * when their PEs are in frozen state. Otherwise, fenced + * PHB might be seen. Those PEs are identified with flag + * EEH_PE_CFG_RESTRICTED, indicating EEH_PE_CFG_BLOCKED + * is set automatically when the PE is put to EEH_PE_ISOLATED. + * + * Restoring BARs possibly triggers PCI config access in + * (OPAL) firmware and then causes fenced PHB. If the + * PCI config is blocked with flag EEH_PE_CFG_BLOCKED, it's + * pointless to restore BARs and dump config space. + */ eeh_ops->configure_bridge(pe); - eeh_pe_restore_bars(pe); + if (!(pe->state & EEH_PE_CFG_BLOCKED)) { + eeh_pe_restore_bars(pe); - pci_regs_buf[0] = 0; - eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen); + pci_regs_buf[0] = 0; + eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen); + } } eeh_ops->get_log(pe, severity, pci_regs_buf, loglen); Patches currently in stable-queue which might be from gwshan@xxxxxxxxxxxxxxxxxx are queue-4.1/powerpc-eeh-probe-after-unbalanced-kref-check.patch queue-4.1/powerpc-eeh-fix-fenced-phb-caused-by-eeh_slot_error_detail.patch queue-4.1/powerpc-pseries-fix-corrupted-pdn-list.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html