4 files changed, 51 insertions, 2 deletions

diff --git a/drivers/scsi/isci/port.c b/drivers/scsi/isci/port.c
index 0a3aec118097..ed206c5a00a6 100644
--- a/drivers/scsi/isci/port.c
+++ b/drivers/scsi/isci/port.c
@@ -1548,6 +1548,29 @@ static void sci_port_failed_state_enter(struct sci_base_state_machine *sm)
         isci_port_hard_reset_complete(iport, SCI_FAILURE_TIMEOUT);
 }
 
+void sci_port_set_hang_detection_timeout(struct isci_port *iport, u32 timeout)
+{
+        int phy_index;
+        u32 phy_mask = iport->active_phy_mask;
+
+        if (timeout)
+                ++iport->hang_detect_users;
+        else if (iport->hang_detect_users > 1)
+                --iport->hang_detect_users;
+        else
+                iport->hang_detect_users = 0;
+
+        if (timeout || (iport->hang_detect_users == 0)) {
+                for (phy_index = 0; phy_index < SCI_MAX_PHYS; phy_index++) {
+                        if ((phy_mask >> phy_index) & 1) {
+                                writel(timeout,
+                                       &iport->phy_table[phy_index]
+                                          ->link_layer_registers
+                                          ->link_layer_hang_detection_timeout);
+                        }
+                }
+        }
+}
 /* --------------------------------------------------------------------------- */
 
 static const struct sci_base_state sci_port_state_table[] = {
@@ -1596,6 +1619,7 @@ void sci_port_construct(struct isci_port *iport, u8 index,
 
         iport->started_request_count = 0;
         iport->assigned_device_count = 0;
+        iport->hang_detect_users = 0;
 
         iport->reserved_rni = SCU_DUMMY_INDEX;
         iport->reserved_tag = SCI_CONTROLLER_INVALID_IO_TAG;
@@ -1733,7 +1757,7 @@ void isci_port_formed(struct asd_sas_phy *phy)
         struct isci_host *ihost = phy->ha->lldd_ha;
         struct isci_phy *iphy = to_iphy(phy);
         struct asd_sas_port *port = phy->port;
-        struct isci_port *iport;
+        struct isci_port *iport = NULL;
         unsigned long flags;
         int i;
 
diff --git a/drivers/scsi/isci/port.h b/drivers/scsi/isci/port.h
index f8bd1e8dbfea..861e8f72811b 100644
--- a/drivers/scsi/isci/port.h
+++ b/drivers/scsi/isci/port.h
@@ -111,6 +111,7 @@ struct isci_port {
         u16 reserved_tag;
         u32 started_request_count;
         u32 assigned_device_count;
+        u32 hang_detect_users;
         u32 not_ready_reason;
         struct isci_phy *phy_table[SCI_MAX_PHYS];
         struct isci_host *owning_controller;
@@ -269,6 +270,10 @@ void sci_port_get_attached_sas_address(
         struct isci_port *iport,
         struct sci_sas_address *sas_address);
 
+void sci_port_set_hang_detection_timeout(
+        struct isci_port *isci_port,
+        u32 timeout);
+
 void isci_port_formed(struct asd_sas_phy *);
 void isci_port_deformed(struct asd_sas_phy *);
 
diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h
index 4a67ff0eb94e..4850b58edbe6 100644
--- a/drivers/scsi/isci/remote_device.h
+++ b/drivers/scsi/isci/remote_device.h
@@ -301,6 +301,13 @@ static inline void sci_remote_device_decrement_request_count(struct isci_remote_
                 idev->started_request_count--;
 }
 
+static inline void isci_dev_set_hang_detection_timeout(
+        struct isci_remote_device *idev,
+        u32 timeout)
+{
+        sci_port_set_hang_detection_timeout(idev->owning_port, timeout);
+}
+
 enum sci_status sci_remote_device_frame_handler(
         struct isci_remote_device *idev,
         u32 frame_index);
diff --git a/drivers/scsi/isci/remote_node_context.c b/drivers/scsi/isci/remote_node_context.c
index 8ce5a35891e1..3a55ba66b8ac 100644
--- a/drivers/scsi/isci/remote_node_context.c
+++ b/drivers/scsi/isci/remote_node_context.c
@@ -316,6 +316,15 @@ static void sci_remote_node_context_tx_rx_suspended_state_enter(struct sci_base_
         sci_remote_node_context_continue_state_transitions(rnc);
 }
 
+static void sci_remote_node_context_await_suspend_state_exit(
+        struct sci_base_state_machine *sm)
+{
+        struct sci_remote_node_context *rnc
+                = container_of(sm, typeof(*rnc), sm);
+
+        isci_dev_set_hang_detection_timeout(rnc_to_dev(rnc), 0);
+}
+
 static const struct sci_base_state sci_remote_node_context_state_table[] = {
         [SCI_RNC_INITIAL] = {
                 .enter_state = sci_remote_node_context_initial_state_enter,
@@ -338,7 +347,9 @@ static const struct sci_base_state sci_remote_node_context_state_table[] = {
         [SCI_RNC_TX_RX_SUSPENDED] = {
                 .enter_state = sci_remote_node_context_tx_rx_suspended_state_enter,
         },
-        [SCI_RNC_AWAIT_SUSPENSION] = { },
+        [SCI_RNC_AWAIT_SUSPENSION] = {
+                .exit_state = sci_remote_node_context_await_suspend_state_exit,
+        },
 };
 
 void sci_remote_node_context_construct(struct sci_remote_node_context *rnc,
@@ -513,6 +524,8 @@ enum sci_status sci_remote_node_context_suspend(struct sci_remote_node_context *
         if (suspend_type == SCI_SOFTWARE_SUSPENSION) {
                 sci_remote_device_post_request(rnc_to_dev(sci_rnc),
                                                     SCU_CONTEXT_COMMAND_POST_RNC_SUSPEND_TX);
+                isci_dev_set_hang_detection_timeout(rnc_to_dev(sci_rnc),
+                                                    0x00000001);
         }
 
         sci_change_state(&sci_rnc->sm, SCI_RNC_AWAIT_SUSPENSION);