powerpc/eeh: Don't collect logs on PE with blocked config space

When the PE's config space is marked as blocked, PCI config read
requests always return 0xFF's. It's pointless to collect logs in
this case.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/eeh.c

@@ -257,6 +257,13 @@ static void *eeh_dump_pe_log(void *data, void *flag)
 	struct eeh_dev *edev, *tmp;
 	size_t *plen = flag;
 
+	/* If the PE's config space is blocked, 0xFF's will be
+	 * returned. It's pointless to collect the log in this
+	 * case.
+	 */
+	if (pe->state & EEH_PE_CFG_BLOCKED)
+		return NULL;
+
 	eeh_pe_for_each_dev(pe, edev, tmp)
 		*plen += eeh_dump_dev_log(edev, pci_regs_buf + *plen,
 					  EEH_PCI_REGS_LOG_LEN - *plen);