[SCSI] isci: revert bcn filtering

The initial bcn filtering implementation was validated on a kernel
baseline that predated the switch to new libata error handling.  Also,
prior to that conversion we borrowed the mvsas MVS_DEV_EH approach to
prevent the unwanted extra ap->ops->phy_reset(ap) that occurred in the
ata_bus_probe() path.

After the conversion to new libata eh resets at discovery are more
frequent and get filtered prematurely by IDEV_EH.  The result is that
our bcn filtering has been blocked from running and at discovery and it
appears to stall discovery completion to the point of triggering hung
task timeouts.  So, revert the implementation for now.  When it returns
it will go into libsas proper.

The domain rediscovery that takes place due to ->lldd_I_T_nexus_reset()
events should now be properly waited for by the ata_port_wait_eh() call
in ata_port_probe().  So the hard coded delay in the isci
->lldd_I_T_nexus_reset() and other libsas drivers should help debounce
the libsas thread from seeing temporary device removals.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 4 insertions, 41 deletions

diff --git a/drivers/scsi/isci/port.c b/drivers/scsi/isci/port.c
index bfeb87905aa..ac7f27749f9 100644
--- a/drivers/scsi/isci/port.c
+++ b/drivers/scsi/isci/port.c
@@ -145,48 +145,15 @@ static void sci_port_bcn_enable(struct isci_port *iport)
 	}
 }
 
-/* called under sci_lock to stabilize phy:port associations */
-void isci_port_bcn_enable(struct isci_host *ihost, struct isci_port *iport)
-{
-	int i;
-
-	clear_bit(IPORT_BCN_BLOCKED, &iport->flags);
-	wake_up(&ihost->eventq);
-
-	if (!test_and_clear_bit(IPORT_BCN_PENDING, &iport->flags))
-		return;
-
-	for (i = 0; i < ARRAY_SIZE(iport->phy_table); i++) {
-		struct isci_phy *iphy = iport->phy_table[i];
-
-		if (!iphy)
-			continue;
-
-		ihost->sas_ha.notify_port_event(&iphy->sas_phy,
-						PORTE_BROADCAST_RCVD);
-		break;
-	}
-}
-
 static void isci_port_bc_change_received(struct isci_host *ihost,
 					 struct isci_port *iport,
 					 struct isci_phy *iphy)
 {
-	if (iport && test_bit(IPORT_BCN_BLOCKED, &iport->flags)) {
-		dev_dbg(&ihost->pdev->dev,
-			"%s: disabled BCN; isci_phy = %p, sas_phy = %p\n",
-			__func__, iphy, &iphy->sas_phy);
-		set_bit(IPORT_BCN_PENDING, &iport->flags);
-		atomic_inc(&iport->event);
-		wake_up(&ihost->eventq);
-	} else {
-		dev_dbg(&ihost->pdev->dev,
-			"%s: isci_phy = %p, sas_phy = %p\n",
-			__func__, iphy, &iphy->sas_phy);
+	dev_dbg(&ihost->pdev->dev,
+		"%s: isci_phy = %p, sas_phy = %p\n",
+		__func__, iphy, &iphy->sas_phy);
 
-		ihost->sas_ha.notify_port_event(&iphy->sas_phy,
-						PORTE_BROADCAST_RCVD);
-	}
+	ihost->sas_ha.notify_port_event(&iphy->sas_phy, PORTE_BROADCAST_RCVD);
 	sci_port_bcn_enable(iport);
 }
 
@@ -278,9 +245,6 @@ static void isci_port_link_down(struct isci_host *isci_host,
 		/* check to see if this is the last phy on this port. */
 		if (isci_phy->sas_phy.port &&
 		    isci_phy->sas_phy.port->num_phys == 1) {
-			atomic_inc(&isci_port->event);
-			isci_port_bcn_enable(isci_host, isci_port);
-
 			/* change the state for all devices on this port.  The
 			 * next task sent to this device will be returned as
 			 * SAS_TASK_UNDELIVERED, and the scsi mid layer will
@@ -1672,7 +1636,6 @@ void isci_port_init(struct isci_port *iport, struct isci_host *ihost, int index)
 	init_completion(&iport->start_complete);
 	iport->isci_host = ihost;
 	isci_port_change_state(iport, isci_freed);
-	atomic_set(&iport->event, 0);
 }
 
 /**