[POWERPC] EEH: Power4 systems sometimes need multiple resets.

On detection of an EEH error, some Power4 systems seem to occasionally
want to be reset twice before they report themselves as fully recovered.
This patch re-arranges the code to attempt additional resets if the first
one doesn't take.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/eeh.c

@@ -478,7 +478,7 @@ eeh_slot_availability(struct pci_dn *pdn)
 
 	printk (KERN_ERR "EEH: Slot unavailable: rc=%d, rets=%d %d %d\n",
 		rc, rets[0], rets[1], rets[2]);
-	return -1;
+	return -2;
 }
 
 /**
@@ -546,11 +546,10 @@ rtas_pci_slot_reset(struct pci_dn *pdn, int state)
 	               BUID_HI(pdn->phb->buid),
 	               BUID_LO(pdn->phb->buid),
 	               state);
-	if (rc) {
-		printk (KERN_WARNING "EEH: Unable to reset the failed slot, (%d) #RST=%d dn=%s\n", 
+	if (rc)
+		printk (KERN_WARNING "EEH: Unable to reset the failed slot,"
+		        " (%d) #RST=%d dn=%s\n",
 		        rc, state, pdn->node->full_name);
-		return;
-	}
 }
 
 /**
@@ -560,11 +559,8 @@ rtas_pci_slot_reset(struct pci_dn *pdn, int state)
  *  Return 0 if success, else a non-zero value.
  */
 
-int
-rtas_set_slot_reset(struct pci_dn *pdn)
+static void __rtas_set_slot_reset(struct pci_dn *pdn)
 {
-	int i, rc;
-
 	rtas_pci_slot_reset (pdn, 1);
 
 	/* The PCI bus requires that the reset be held high for at least
@@ -585,17 +581,33 @@ rtas_set_slot_reset(struct pci_dn *pdn)
 	 * up traffic. */
 #define PCI_BUS_SETTLE_TIME_MSEC 1800
 	msleep (PCI_BUS_SETTLE_TIME_MSEC);
+}
+
+int rtas_set_slot_reset(struct pci_dn *pdn)
+{
+	int i, rc;
+
+	__rtas_set_slot_reset(pdn);
 
 	/* Now double check with the firmware to make sure the device is
 	 * ready to be used; if not, wait for recovery. */
 	for (i=0; i<10; i++) {
 		rc = eeh_slot_availability (pdn);
-		if (rc < 0)
-			printk (KERN_ERR "EEH: failed (%d) to reset slot %s\n", rc, pdn->node->full_name);
 		if (rc == 0)
 			return 0;
-		if (rc < 0)
+
+		if (rc == -2) {
+			printk (KERN_ERR "EEH: failed (%d) to reset slot %s\n",
+			        i, pdn->node->full_name);
+			__rtas_set_slot_reset(pdn);
+			continue;
+		}
+
+		if (rc < 0) {
+			printk (KERN_ERR "EEH: unrecoverable slot failure %s\n",
+			        pdn->node->full_name);
 			return -1;
+		}
 
 		msleep (rc+100);
 	}