3 files changed, 63 insertions, 6 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index a8ace8d24e66..48cadf88c399 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -679,3 +679,22 @@ int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 
         return rtn;
 }
+
+void sas_ata_schedule_reset(struct domain_device *dev)
+{
+        struct ata_eh_info *ehi;
+        struct ata_port *ap;
+        unsigned long flags;
+
+        if (!dev_is_sata(dev))
+                return;
+
+        ap = dev->sata_dev.ap;
+        ehi = &ap->link.eh_info;
+
+        spin_lock_irqsave(ap->lock, flags);
+        ehi->err_mask |= AC_ERR_TIMEOUT;
+        ehi->action |= ATA_EH_RESET;
+        ata_port_schedule_eh(ap);
+        spin_unlock_irqrestore(ap->lock, flags);
+}
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index e45b259dac4c..f4894b0f537b 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -28,6 +28,7 @@
 
 #include "sas_internal.h"
 
+#include <scsi/sas_ata.h>
 #include <scsi/scsi_transport.h>
 #include <scsi/scsi_transport_sas.h>
 #include "../scsi_sas_internal.h"
@@ -226,12 +227,35 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
         return;
 }
 
+/* check if we have an existing attached ata device on this expander phy */
+static struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id)
+{
+        struct ex_phy *ex_phy = &ex_dev->ex_dev.ex_phy[phy_id];
+        struct domain_device *dev;
+        struct sas_rphy *rphy;
+
+        if (!ex_phy->port)
+                return NULL;
+
+        rphy = ex_phy->port->rphy;
+        if (!rphy)
+                return NULL;
+
+        dev = sas_find_dev_by_rphy(rphy);
+
+        if (dev && dev_is_sata(dev))
+                return dev;
+
+        return NULL;
+}
+
 #define DISCOVER_REQ_SIZE  16
 #define DISCOVER_RESP_SIZE 56
 
 static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
                                       u8 *disc_resp, int single)
 {
+        struct domain_device *ata_dev = sas_ex_to_ata(dev, single);
         int i, res;
 
         disc_req[9] = single;
@@ -242,20 +266,30 @@ static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
                                        disc_resp, DISCOVER_RESP_SIZE);
                 if (res)
                         return res;
-                /* This is detecting a failure to transmit initial
-                 * dev to host FIS as described in section G.5 of
-                 * sas-2 r 04b */
                 dr = &((struct smp_resp *)disc_resp)->disc;
                 if (memcmp(dev->sas_addr, dr->attached_sas_addr,
                           SAS_ADDR_SIZE) == 0) {
                         sas_printk("Found loopback topology, just ignore it!\n");
                         return 0;
                 }
+
+                /* This is detecting a failure to transmit initial
+                 * dev to host FIS as described in section J.5 of
+                 * sas-2 r16
+                 */
                 if (!(dr->attached_dev_type == 0 &&
                       dr->attached_sata_dev))
                         break;
-                /* In order to generate the dev to host FIS, we
-                 * send a link reset to the expander port */
+
+                /* In order to generate the dev to host FIS, we send a
+                 * link reset to the expander port.  If a device was
+                 * previously detected on this port we ask libata to
+                 * manage the reset and link recovery.
+                 */
+                if (ata_dev) {
+                        sas_ata_schedule_reset(ata_dev);
+                        break;
+                }
                 sas_smp_phy_control(dev, single, PHY_FUNC_LINK_RESET, NULL);
                 /* Wait for the reset to trigger the negotiation */
                 msleep(500);
diff --git a/include/scsi/sas_ata.h b/include/scsi/sas_ata.h
index 9f7a23d1146d..c0bcd30eec56 100644
--- a/include/scsi/sas_ata.h
+++ b/include/scsi/sas_ata.h
@@ -44,7 +44,7 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost);
 int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
                struct list_head *done_q);
 void sas_probe_sata(struct work_struct *work);
-
+void sas_ata_schedule_reset(struct domain_device *dev);
 #else
 
 
@@ -75,6 +75,10 @@ static inline void sas_probe_sata(struct work_struct *work)
 {
 }
 
+static inline void sas_ata_schedule_reset(struct domain_device *dev)
+{
+}
+
 #endif
 
 #endif /* _SAS_ATA_H_ */