From: mchristi@redhat.com <mchristi@redhat.com>
Date: Thu, 11 Dec 2008 10:21:58 -0600
Subject: [scsi] fnic: remove link down count processing
Message-id: 12290125182607-git-send-email-mchristi@redhat.com
O-Subject: [PATCH] RHEL 5.3 fnic: Remove link down count processing
Bugzilla: 474935
RH-Acked-by: Rob Evers <revers@redhat.com>
RH-Acked-by: Tomas Henzl <thenzl@redhat.com>

From: Mike Christie <mchristi@redhat.com>

This is for BZ 474935.

>From Cisco:

This fixes a regression that was introduced in snapshot 6.

This removes the link down count processing that was added in
snap 6, and sets the lport retry count to a fixed value in fnic,
instead of picking the value from fw config, since incoming Plogis
from initiators are not supported in libFC. So, whenever there are
more than 1 libFC based initiators on the fabric, they keep trying to Plogi
to each other, but never succeed. So, set the retry count to a
small value, so that they give up.
..............

The patch was made and tested by Cisco. The driver is new in 5.3
and this patch only affects it. I do not have local access to test
it here. We have been relying on Cisco for testing. I have only
compile tested the patch.

diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h
index ec6671e..b70ad06 100644
--- a/drivers/scsi/fnic/fnic.h
+++ b/drivers/scsi/fnic/fnic.h
@@ -126,11 +126,6 @@ enum fnic_state {
 #define FNIC_RQ_MAX 1
 #define FNIC_CQ_MAX (FNIC_WQ_COPY_MAX + FNIC_WQ_MAX + FNIC_RQ_MAX)
 
-enum fnic_link_state {
-	FNIC_LINK_DOWN = 0,
-	FNIC_LINK_UP
-};
-
 /* Per-instance private data structure */
 struct fnic {
 	struct fc_lport *lport;
@@ -161,8 +156,6 @@ struct fnic {
 
 	struct fc_frame *flogi;
 	struct fc_frame *flogi_resp;
-	enum fnic_link_state link_state;
-	u32  link_down_cnt;
 	u16 flogi_oxid;
 	unsigned long s_id;
 	enum fnic_state state;
diff --git a/drivers/scsi/fnic/fnic_main.c b/drivers/scsi/fnic/fnic_main.c
index 7d6b378..0f21883 100644
--- a/drivers/scsi/fnic/fnic_main.c
+++ b/drivers/scsi/fnic/fnic_main.c
@@ -250,89 +250,37 @@ void fnic_log_q_error(struct fnic *fnic)
 static void fnic_handle_link_event(struct fnic *fnic)
 {
 	int link_status = vnic_dev_link_status(fnic->vdev);
-	u32 link_down_cnt = vnic_dev_link_down_cnt(fnic->vdev);
 	struct fnic_event *event;
-	u8 list_was_empty = 0;
+	u8 list_was_empty;
 	unsigned long flags;
-	u8 send_link_up = 0;
-	u8 send_link_down = 0;
 
 	FNIC_DEBUG_MAIN(DFX "link %s\n", fnic->fnic_no,
 			(link_status ? "up" : "down"));
 
-	spin_lock_irqsave(&fnic->fnic_lock, flags);
-	if (fnic->in_remove) {
-		fnic->link_down_cnt = link_down_cnt;
-		spin_unlock_irqrestore(&fnic->fnic_lock, flags);
+	if (fnic->in_remove)
 		return;
-	}
 
-	/*
-	 * If link was down, and down event, do nothing
-	 * If link was down, and up event, send up event
-	 * if link was up, and down event, send down event
-	 * If link was up, and up event, and link down cnt matches, do nothing
-	 * If link was up, and up event, and link down cnt does not match,
-	 * send down followed by up
-	 */
-	if (fnic->link_state == FNIC_LINK_DOWN) {
-		if (!link_status) {
-			fnic->link_down_cnt = link_down_cnt;
-			spin_unlock_irqrestore(&fnic->fnic_lock, flags);
-			return;
-		} else
-			send_link_up = 1;
-	} else {
-		if (!link_status) {
-			send_link_down = 1;
-		} else if (link_down_cnt != fnic->link_down_cnt) {
-			send_link_down = 1;
-			send_link_up = 1;
-		} else {
-			fnic->link_down_cnt = link_down_cnt;
-			spin_unlock_irqrestore(&fnic->fnic_lock, flags);
-			return;
-		}
+	event = kmem_cache_alloc(fnic_ev_cache, GFP_ATOMIC);
+	if (!event) {
+		FNIC_DEBUG_MAIN(DFX "Cannot allocate a event, "
+				"cannot indicate link event to FCS\n",
+				fnic->fnic_no);
+		return;
 	}
-	fnic->link_down_cnt = link_down_cnt;
-	spin_unlock_irqrestore(&fnic->fnic_lock, flags);
 
-	if (send_link_down) {
-		event = kmem_cache_alloc(fnic_ev_cache, GFP_ATOMIC);
-		if (!event) {
-			FNIC_DEBUG_MAIN(DFX "Cannot allocate a event, "
-					"cannot indicate link down to FCS\n",
-					fnic->fnic_no);
-			return;
-		}
-		memset(event, 0, sizeof(struct fnic_event));
-		event->fnic = fnic;
+	/* Pass the event to thread */
+	memset(event, 0, sizeof(struct fnic_event));
+	event->fnic = fnic;
+	event->ev_type = EV_TYPE_LINK_UP;
+	if (!link_status) {
 		event->ev_type = EV_TYPE_LINK_DOWN;
 		fnic->lport->host_stats.link_failure_count++;
-
-		spin_lock_irqsave(&fnic_eventlist_lock, flags);
-		list_was_empty = list_empty(&fnic_eventlist);
-		list_add_tail(&event->list, &fnic_eventlist);
-		spin_unlock_irqrestore(&fnic_eventlist_lock, flags);
 	}
 
-	if (send_link_up) {
-		event = kmem_cache_alloc(fnic_ev_cache, GFP_ATOMIC);
-		if (!event) {
-			FNIC_DEBUG_MAIN(DFX "Cannot allocate a event, "
-					"cannot indicate link up to FCS\n",
-					fnic->fnic_no);
-			return;
-		}
-		memset(event, 0, sizeof(struct fnic_event));
-		event->fnic = fnic;
-		event->ev_type = EV_TYPE_LINK_UP;
-
-		spin_lock_irqsave(&fnic_eventlist_lock, flags);
-		list_was_empty |= list_empty(&fnic_eventlist);
-		list_add_tail(&event->list, &fnic_eventlist);
-		spin_unlock_irqrestore(&fnic_eventlist_lock, flags);
-	}
+	spin_lock_irqsave(&fnic_eventlist_lock, flags);
+	list_was_empty = list_empty(&fnic_eventlist);
+	list_add_tail(&event->list, &fnic_eventlist);
+	spin_unlock_irqrestore(&fnic_eventlist_lock, flags);
 
 	if (list_was_empty)
 		wake_up_process(fnic_thread);
@@ -732,8 +680,6 @@ static int __devinit fnic_probe(struct pci_dev *pdev,
 	fnic->flogi = NULL;
 	fnic->flogi_resp = NULL;
 	fnic->state = FNIC_IN_FC_MODE;
-	fnic->link_state = FNIC_LINK_DOWN;
-	fnic->link_down_cnt = 0;
 
 	/* Enable hardware stripping of vlan header on ingress */
 	fnic_set_nic_cfg(fnic, 0, 0, 0, 0, 0, 0, 1);
@@ -786,7 +732,7 @@ static int __devinit fnic_probe(struct pci_dev *pdev,
 		goto err_out_remove_scsi_host;
 	}
 
-	lp->max_retry_count = fnic->config.flogi_retries;
+	lp->max_retry_count = 3;
 	lp->service_params = (FCP_SPPF_INIT_FCN | FCP_SPPF_RD_XRDY_DIS |
 			      FCP_SPPF_CONF_COMPL);
 	if (fnic->config.flags & VFCF_FCP_SEQ_LVL_ERR)