2 files changed, 86 insertions, 0 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.h b/drivers/scsi/mpt2sas/mpt2sas_base.h
index 2616bb1597b0..454a74a3ec50 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.h
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.h
@@ -366,6 +366,7 @@ struct _sas_port {
  * @phy_id: unique phy id
  * @handle: device handle for this phy
  * @attached_handle: device handle for attached device
+ * @phy_belongs_to_port: port has been created for this phy
  */
 struct _sas_phy {
         struct list_head port_siblings;
@@ -375,6 +376,7 @@ struct _sas_phy {
         u8      phy_id;
         u16     handle;
         u16     attached_handle;
+        u8      phy_belongs_to_port;
 };
 
 /**
diff --git a/drivers/scsi/mpt2sas/mpt2sas_transport.c b/drivers/scsi/mpt2sas/mpt2sas_transport.c
index bb2d2c93718b..2727c3b65104 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_transport.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_transport.c
@@ -465,6 +465,85 @@ _transport_expander_report_manufacture(struct MPT2SAS_ADAPTER *ioc,
         return rc;
 }
 
+
+/**
+ * _transport_delete_duplicate_port - (see below description)
+ * @ioc: per adapter object
+ * @sas_node: sas node object (either expander or sas host)
+ * @sas_address: sas address of device being added
+ * @phy_num: phy number
+ *
+ * This function is called when attempting to add a new port that is claiming
+ * the same phy resources already in use by another port.  If we don't release
+ * the claimed phy resources, the sas transport layer will hang from the BUG
+ * in sas_port_add_phy.
+ *
+ * The reason we would hit this issue is becuase someone is changing the
+ * sas address of a device on the fly, meanwhile controller firmware sends
+ * EVENTs out of order when removing the previous instance of the device.
+ */
+static void
+_transport_delete_duplicate_port(struct MPT2SAS_ADAPTER *ioc,
+    struct _sas_node *sas_node, u64 sas_address, int phy_num)
+{
+        struct _sas_port *mpt2sas_port, *mpt2sas_port_duplicate;
+        struct _sas_phy *mpt2sas_phy;
+
+        printk(MPT2SAS_ERR_FMT "new device located at sas_addr(0x%016llx), "
+            "phy_id(%d)\n", ioc->name, (unsigned long long)sas_address,
+            phy_num);
+
+        mpt2sas_port_duplicate = NULL;
+        list_for_each_entry(mpt2sas_port, &sas_node->sas_port_list, port_list) {
+                dev_printk(KERN_ERR, &mpt2sas_port->port->dev,
+                    "existing device at sas_addr(0x%016llx), num_phys(%d)\n",
+                    (unsigned long long)
+                    mpt2sas_port->remote_identify.sas_address,
+                    mpt2sas_port->num_phys);
+                list_for_each_entry(mpt2sas_phy, &mpt2sas_port->phy_list,
+                    port_siblings) {
+                        dev_printk(KERN_ERR, &mpt2sas_phy->phy->dev,
+                            "phy_number(%d)\n", mpt2sas_phy->phy_id);
+                        if (mpt2sas_phy->phy_id == phy_num)
+                                mpt2sas_port_duplicate = mpt2sas_port;
+                }
+        }
+
+        if (!mpt2sas_port_duplicate)
+                return;
+
+        dev_printk(KERN_ERR, &mpt2sas_port_duplicate->port->dev,
+            "deleting duplicate device at sas_addr(0x%016llx), phy(%d)!!!!\n",
+            (unsigned long long)
+            mpt2sas_port_duplicate->remote_identify.sas_address, phy_num);
+        ioc->logging_level |= MPT_DEBUG_TRANSPORT;
+        mpt2sas_transport_port_remove(ioc,
+            mpt2sas_port_duplicate->remote_identify.sas_address,
+            sas_node->sas_address);
+        ioc->logging_level &= ~MPT_DEBUG_TRANSPORT;
+}
+
+/**
+ * _transport_sanity_check - sanity check when adding a new port
+ * @ioc: per adapter object
+ * @sas_node: sas node object (either expander or sas host)
+ * @sas_address: sas address of device being added
+ *
+ * See the explanation above from _transport_delete_duplicate_port
+ */
+static void
+_transport_sanity_check(struct MPT2SAS_ADAPTER *ioc, struct _sas_node *sas_node,
+     u64 sas_address)
+{
+        int i;
+
+        for (i = 0; i < sas_node->num_phys; i++)
+                if (sas_node->phy[i].remote_identify.sas_address == sas_address)
+                        if (sas_node->phy[i].phy_belongs_to_port)
+                                _transport_delete_duplicate_port(ioc, sas_node,
+                                        sas_address, i);
+}
+
 /**
  * mpt2sas_transport_port_add - insert port to the list
  * @ioc: per adapter object
@@ -522,6 +601,9 @@ mpt2sas_transport_port_add(struct MPT2SAS_ADAPTER *ioc, u16 handle,
                 goto out_fail;
         }
 
+        _transport_sanity_check(ioc, sas_node,
+            mpt2sas_port->remote_identify.sas_address);
+
         for (i = 0; i < sas_node->num_phys; i++) {
                 if (sas_node->phy[i].remote_identify.sas_address !=
                     mpt2sas_port->remote_identify.sas_address)
@@ -553,6 +635,7 @@ mpt2sas_transport_port_add(struct MPT2SAS_ADAPTER *ioc, u16 handle,
                             mpt2sas_port->remote_identify.sas_address,
                             mpt2sas_phy->phy_id);
                 sas_port_add_phy(port, mpt2sas_phy->phy);
+                mpt2sas_phy->phy_belongs_to_port = 1;
         }
 
         mpt2sas_port->port = port;
@@ -651,6 +734,7 @@ mpt2sas_transport_port_remove(struct MPT2SAS_ADAPTER *ioc, u64 sas_address,
                             (unsigned long long)
                             mpt2sas_port->remote_identify.sas_address,
                             mpt2sas_phy->phy_id);
+                mpt2sas_phy->phy_belongs_to_port = 0;
                 sas_port_delete_phy(mpt2sas_port->port, mpt2sas_phy->phy);
                 list_del(&mpt2sas_phy->port_siblings);
         }