[PATCH 4/8] scsi: libsas: trigger a new revalidation to discover the device

[Jason Yan <yanaijie@huawei.com>]

Now if a new device replaced a old device, the sas address will change.
We unregister the old device and discover the new device in one
revalidation process. But after we deferred the sas_port_delete(), the
sas port is not deleted when we registering the new port and device.
This will make the sysfs complain of creating duplicate filename.

Fix this by doing the replacement in two steps. The first revalidation
only delete the old device and trigger a new revalidation. The second
revalidation discover the new device.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: chenxiang <chenxiang66@hisilicon.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: Hannes Reinecke <hare@suse.com>
---
 drivers/scsi/libsas/sas_expander.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 629c580d906b..25ad9ef54e6c 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -2013,6 +2013,8 @@ static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last)
 {
 	struct expander_device *ex = &dev->ex_dev;
 	struct ex_phy *phy = &ex->ex_phy[phy_id];
+	struct asd_sas_port *port = dev->port;
+	struct asd_sas_phy *sas_phy;
 	enum sas_device_type type = SAS_PHY_UNUSED;
 	u8 sas_addr[8];
 	int res;
@@ -2060,7 +2062,14 @@ static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last)
 		    SAS_ADDR(phy->attached_sas_addr));
 	sas_unregister_devs_sas_addr(dev, phy_id, last);
 
-	return sas_discover_new(dev, phy_id);
+	/* force the next revalidation find this phy and bring it up */
+	phy->phy_change_count = -1;
+	ex->ex_change_count = -1;
+	sas_phy = container_of(port->phy_list.next, struct asd_sas_phy,
+			port_phy_el);
+	port->ha->notify_port_event(sas_phy, PORTE_BROADCAST_RCVD);
+
+	return 0;
 }
 
 /**
-- 
2.13.6