3 files changed, 56 insertions, 5 deletions

diff --git a/drivers/scsi/aic94xx/aic94xx.h b/drivers/scsi/aic94xx/aic94xx.h
index 32f513b1b78a..eb8efdcefe48 100644
--- a/drivers/scsi/aic94xx/aic94xx.h
+++ b/drivers/scsi/aic94xx/aic94xx.h
@@ -102,6 +102,7 @@ int  asd_abort_task_set(struct domain_device *, u8 *lun);
 int  asd_clear_aca(struct domain_device *, u8 *lun);
 int  asd_clear_task_set(struct domain_device *, u8 *lun);
 int  asd_lu_reset(struct domain_device *, u8 *lun);
+int  asd_I_T_nexus_reset(struct domain_device *dev);
 int  asd_query_task(struct sas_task *);
 
 /* ---------- Adapter and Port management ---------- */
diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c
index 5d761eb67442..88d1e731b65e 100644
--- a/drivers/scsi/aic94xx/aic94xx_init.c
+++ b/drivers/scsi/aic94xx/aic94xx_init.c
@@ -1003,7 +1003,7 @@ static struct sas_domain_function_template aic94xx_transport_functions = {
         .lldd_abort_task_set    = asd_abort_task_set,
         .lldd_clear_aca         = asd_clear_aca,
         .lldd_clear_task_set    = asd_clear_task_set,
-        .lldd_I_T_nexus_reset   = NULL,
+        .lldd_I_T_nexus_reset   = asd_I_T_nexus_reset,
         .lldd_lu_reset          = asd_lu_reset,
         .lldd_query_task        = asd_query_task,
 
diff --git a/drivers/scsi/aic94xx/aic94xx_tmf.c b/drivers/scsi/aic94xx/aic94xx_tmf.c
index 144f5ad20453..d684c7432e63 100644
--- a/drivers/scsi/aic94xx/aic94xx_tmf.c
+++ b/drivers/scsi/aic94xx/aic94xx_tmf.c
@@ -140,8 +140,14 @@ int asd_clear_nexus_port(struct asd_sas_port *port)
         CLEAR_NEXUS_POST;
 }
 
-#if 0
-static int asd_clear_nexus_I_T(struct domain_device *dev)
+enum clear_nexus_phase {
+        NEXUS_PHASE_PRE,
+        NEXUS_PHASE_POST,
+        NEXUS_PHASE_RESUME,
+};
+
+static int asd_clear_nexus_I_T(struct domain_device *dev,
+                               enum clear_nexus_phase phase)
 {
         struct asd_ha_struct *asd_ha = dev->port->ha->lldd_ha;
         struct asd_ascb *ascb;
@@ -150,12 +156,56 @@ static int asd_clear_nexus_I_T(struct domain_device *dev)
 
         CLEAR_NEXUS_PRE;
         scb->clear_nexus.nexus = NEXUS_I_T;
-        scb->clear_nexus.flags = SEND_Q | EXEC_Q | NOTINQ;
+        switch (phase) {
+        case NEXUS_PHASE_PRE:
+                scb->clear_nexus.flags = EXEC_Q | SUSPEND_TX;
+                break;
+        case NEXUS_PHASE_POST:
+                scb->clear_nexus.flags = SEND_Q | NOTINQ;
+                break;
+        case NEXUS_PHASE_RESUME:
+                scb->clear_nexus.flags = RESUME_TX;
+        }
         scb->clear_nexus.conn_handle = cpu_to_le16((u16)(unsigned long)
                                                    dev->lldd_dev);
         CLEAR_NEXUS_POST;
 }
-#endif
+
+int asd_I_T_nexus_reset(struct domain_device *dev)
+{
+        int res, tmp_res, i;
+        struct sas_phy *phy = sas_find_local_phy(dev);
+        /* Standard mandates link reset for ATA  (type 0) and
+         * hard reset for SSP (type 1) */
+        int reset_type = (dev->dev_type == SATA_DEV ||
+                          (dev->tproto & SAS_PROTOCOL_STP)) ? 0 : 1;
+
+        asd_clear_nexus_I_T(dev, NEXUS_PHASE_PRE);
+        /* send a hard reset */
+        ASD_DPRINTK("sending %s reset to %s\n",
+                    reset_type ? "hard" : "soft", phy->dev.bus_id);
+        res = sas_phy_reset(phy, reset_type);
+        if (res == TMF_RESP_FUNC_COMPLETE) {
+                /* wait for the maximum settle time */
+                msleep(500);
+                /* clear all outstanding commands (keep nexus suspended) */
+                asd_clear_nexus_I_T(dev, NEXUS_PHASE_POST);
+        }
+        for (i = 0 ; i < 3; i++) {
+                tmp_res = asd_clear_nexus_I_T(dev, NEXUS_PHASE_RESUME);
+                if (tmp_res == TC_RESUME)
+                        return res;
+                msleep(500);
+        }
+
+        /* This is a bit of a problem:  the sequencer is still suspended
+         * and is refusing to resume.  Hope it will resume on a bigger hammer
+         * or the disk is lost */
+        dev_printk(KERN_ERR, &phy->dev,
+                   "Failed to resume nexus after reset 0x%x\n", tmp_res);
+
+        return TMF_RESP_FUNC_FAILED;
+}
 
 static int asd_clear_nexus_I_T_L(struct domain_device *dev, u8 *lun)
 {