[PATCH 02/10] powerpc/eeh: Don't collect PCI-CFG data on PHB

[Gavin Shan <shangw@linux.vnet.ibm.com>]

When the PHB is fenced or dead, it's pointless to collect the data
from PCI config space of subordinate PCI devices since it should
return 0xFF's. It also has potential risk to incur additional errors.
The patch avoids collecting PCI-CFG data while PHB is in fenced or
dead state.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/eeh.c |   34 ++++++++++++++++++++++++----------
 1 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 951a632..65320fd 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -232,16 +232,30 @@ void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
 {
 	size_t loglen = 0;
 	struct eeh_dev *edev;
+	bool valid_cfg_log = true;
 
-	eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
-	eeh_ops->configure_bridge(pe);
-	eeh_pe_restore_bars(pe);
-
-	pci_regs_buf[0] = 0;
-	eeh_pe_for_each_dev(pe, edev) {
-		loglen += eeh_gather_pci_data(edev, pci_regs_buf,
-				EEH_PCI_REGS_LOG_LEN);
-        }
+	/*
+	 * When the PHB is fenced or dead, it's pointless to collect
+	 * the data from PCI config space because it should return
+	 * 0xFF's. The potential risk of that is introducing additional
+	 * errors.
+	 */
+	if (eeh_probe_mode_dev() &&
+	    (pe->type & EEH_PE_PHB) &&
+	    (pe->state & (EEH_PE_ISOLATED | EEH_PE_PHB_DEAD)))
+		valid_cfg_log = false;
+
+	if (valid_cfg_log) {
+		eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
+		eeh_ops->configure_bridge(pe);
+		eeh_pe_restore_bars(pe);
+
+		pci_regs_buf[0] = 0;
+		eeh_pe_for_each_dev(pe, edev) {
+			loglen += eeh_gather_pci_data(edev, pci_regs_buf,
+						      EEH_PCI_REGS_LOG_LEN);
+		}
+	}
 
 	eeh_ops->get_log(pe, severity, pci_regs_buf, loglen);
 }
-- 
1.7.5.4