[SCSI] libsas: Add an LU reset mechanism to the error handler

After discussion with andmike and dougg, it seems that the purpose of
eh_device_reset_handler is to issue LU resets, and that
eh_bus_reset_handler would be a more appropriate place for a phy reset.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 37 insertions, 4 deletions

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index cd2378010c7e..897a5e2c55e4 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -421,16 +421,37 @@ struct sas_phy *find_local_sas_phy(struct domain_device *dev)
         return exphy->phy;
 }
 
-/* Attempt to send a target reset message to a device */
+/* Attempt to send a LUN reset message to a device */
 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
 {
         struct domain_device *dev = cmd_to_domain_dev(cmd);
+        struct sas_internal *i =
+                to_sas_internal(dev->port->ha->core.shost->transportt);
+        struct scsi_lun lun;
+        int res;
+
+        int_to_scsilun(cmd->device->lun, &lun);
+
+        if (!i->dft->lldd_lu_reset)
+                return FAILED;
+
+        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
+        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
+                return SUCCESS;
+
+        return FAILED;
+}
+
+/* Attempt to send a phy (bus) reset */
+int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
+{
+        struct domain_device *dev = cmd_to_domain_dev(cmd);
         struct sas_phy *phy = find_local_sas_phy(dev);
         int res;
 
         res = sas_phy_reset(phy, 1);
         if (res)
-                SAS_DPRINTK("Device reset of %s failed 0x%x\n",
+                SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
                             phy->dev.kobj.k_name,
                             res);
         if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
@@ -443,10 +464,20 @@ int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
 static int try_to_reset_cmd_device(struct Scsi_Host *shost,
                                    struct scsi_cmnd *cmd)
 {
+        int res;
+
         if (!shost->hostt->eh_device_reset_handler)
-                return FAILED;
+                goto try_bus_reset;
+
+        res = shost->hostt->eh_device_reset_handler(cmd);
+        if (res == SUCCESS)
+                return res;
 
-        return shost->hostt->eh_device_reset_handler(cmd);
+try_bus_reset:
+        if (shost->hostt->eh_bus_reset_handler)
+                return shost->hostt->eh_bus_reset_handler(cmd);
+
+        return FAILED;
 }
 
 static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
@@ -976,3 +1007,4 @@ EXPORT_SYMBOL_GPL(sas_task_abort);
 EXPORT_SYMBOL_GPL(sas_phy_reset);
 EXPORT_SYMBOL_GPL(sas_phy_enable);
 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
+EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index b200233cc6f4..8516ba68cc95 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -661,5 +661,6 @@ void sas_init_dev(struct domain_device *);
 void sas_task_abort(struct sas_task *);
 int __sas_task_abort(struct sas_task *);
 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd);
+int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd);
 
 #endif /* _SASLIB_H_ */