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);