phb4: Rework retries so we can do more than one

This reworks the pci link training retry code so that we can do more
than one retry.

This will now also print an error if a link fails to train.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

hw/phb4.c

@@ -2166,13 +2166,12 @@ static int64_t phb4_retry_state(struct pci_slot *slot)
 {
 	struct phb4 *p = phb_to_phb4(slot->phb);
 
-	if (slot->retry_state == PCI_SLOT_STATE_NORMAL)
-		return OPAL_WRONG_STATE;
+	if (!slot->link_retries--) {
+		PHBERR(p, "Link detected but won't train\n");
+		return OPAL_HARDWARE;
+	}
 
-	PHBDBG(p, "Retry state %08x\n", slot->retry_state);
-	slot->delay_tgt_tb = 0;
-	pci_slot_set_state(slot, slot->retry_state);
-	slot->retry_state = PCI_SLOT_STATE_NORMAL;
+	pci_slot_set_state(slot, PHB4_SLOT_CRESET_START);
 	return pci_slot_set_sm_timeout(slot, msecs_to_tb(1));
 }
 
@@ -2325,7 +2324,7 @@ static int64_t phb4_freset(struct pci_slot *slot)
 		}
 
 		PHBDBG(p, "FRESET: Prepare for link down\n");
-		slot->retry_state = PHB4_SLOT_CRESET_START;
+
 		if (slot->ops.prepare_link_change)
 			slot->ops.prepare_link_change(slot, false);
 		/* fall through */
@@ -2513,6 +2512,7 @@ static struct pci_slot *phb4_slot_create(struct phb *phb)
 	slot->ops.hreset		= phb4_hreset;
 	slot->ops.freset		= phb4_freset;
 	slot->ops.creset		= phb4_creset;
+	slot->link_retries		= 1;
 
 	return slot;
 }

include/pci-slot.h

@@ -184,6 +184,7 @@ struct pci_slot {
 	uint32_t		slot_cap;
 	uint64_t		delay_tgt_tb;
 	uint64_t		retries;
+	uint64_t		link_retries;
 	struct pci_slot_ops	ops;
 	void			*data;
 };