[SCSI] Mention scsi_scan_host() in scsi_mid_low_api.txt

Update to mention scsi_scan_host()
Signed-off-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Documentation/scsi/scsi_mid_low_api.txt

@@ -150,7 +150,8 @@ scsi devices of which only the first 2 respond:
 LLD                   mid level                    LLD
 ===-------------------=========--------------------===------
 scsi_host_alloc()  -->
-scsi_add_host()  --------+
+scsi_add_host()  ---->
+scsi_scan_host()  -------+
                          |
                     slave_alloc()
                     slave_configure() -->  scsi_adjust_queue_depth()
@@ -196,7 +197,7 @@ of the issues involved. See the section on reference counting below.
 
 
 The hotplug concept may be extended to SCSI devices. Currently, when an
-HBA is added, the scsi_add_host() function causes a scan for SCSI devices
+HBA is added, the scsi_scan_host() function causes a scan for SCSI devices
 attached to the HBA's SCSI transport. On newer SCSI transports the HBA
 may become aware of a new SCSI device _after_ the scan has completed.
 An LLD can use this sequence to make the mid level aware of a SCSI device:
@@ -372,7 +373,7 @@ names all start with "scsi_".
 Summary:
    scsi_activate_tcq - turn on tag command queueing
    scsi_add_device - creates new scsi device (lu) instance
-   scsi_add_host - perform sysfs registration and SCSI bus scan.
+   scsi_add_host - perform sysfs registration and set up transport class
    scsi_adjust_queue_depth - change the queue depth on a SCSI device
    scsi_assign_lock - replace default host_lock with given lock
    scsi_bios_ptable - return copy of block device's partition table
@@ -386,6 +387,7 @@ Summary:
    scsi_remove_device - detach and remove a SCSI device
    scsi_remove_host - detach and remove all SCSI devices owned by host
    scsi_report_bus_reset - report scsi _bus_ reset observed
+   scsi_scan_host - scan SCSI bus
    scsi_track_queue_full - track successive QUEUE_FULL events 
    scsi_unblock_requests - allow further commands to be queued to given host
    scsi_unregister - [calls scsi_host_put()]
@@ -425,10 +427,10 @@ void scsi_activate_tcq(struct scsi_device *sdev, int depth)
  *      Might block: yes
  *
  *      Notes: This call is usually performed internally during a scsi
- *      bus scan when an HBA is added (i.e. scsi_add_host()). So it
+ *      bus scan when an HBA is added (i.e. scsi_scan_host()). So it
  *      should only be called if the HBA becomes aware of a new scsi
- *      device (lu) after scsi_add_host() has completed. If successful
- *      this call we lead to slave_alloc() and slave_configure() callbacks
+ *      device (lu) after scsi_scan_host() has completed. If successful
+ *      this call can lead to slave_alloc() and slave_configure() callbacks
  *      into the LLD.
  *
  *      Defined in: drivers/scsi/scsi_scan.c
@@ -439,7 +441,7 @@ struct scsi_device * scsi_add_device(struct Scsi_Host *shost,
 
 
 /**
- * scsi_add_host - perform sysfs registration and SCSI bus scan.
+ * scsi_add_host - perform sysfs registration and set up transport class
  * @shost:   pointer to scsi host instance
  * @dev:     pointer to struct device of type scsi class
  *
@@ -448,7 +450,11 @@ struct scsi_device * scsi_add_device(struct Scsi_Host *shost,
  *      Might block: no
  *
  *      Notes: Only required in "hotplug initialization model" after a
- *      successful call to scsi_host_alloc().
+ *      successful call to scsi_host_alloc().  This function does not
+ *	scan the bus; this can be done by calling scsi_scan_host() or
+ *	in some other transport-specific way.  The LLD must set up
+ *	the transport template before calling this function and may only
+ *	access the transport class data after this function has been called.
  *
  *      Defined in: drivers/scsi/hosts.c
  **/
@@ -559,7 +565,7 @@ void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
  *      area for the LLD's exclusive use.
  *      Both associated refcounting objects have their refcount set to 1.
  *      Full registration (in sysfs) and a bus scan are performed later when
- *      scsi_add_host() is called.
+ *      scsi_add_host() and scsi_scan_host() are called.
  *
  *      Defined in: drivers/scsi/hosts.c .
  **/
@@ -698,6 +704,19 @@ int scsi_remove_host(struct Scsi_Host *shost)
 void scsi_report_bus_reset(struct Scsi_Host * shost, int channel)
 
 
+/**
+ * scsi_scan_host - scan SCSI bus
+ * @shost: a pointer to a scsi host instance
+ *
+ *	Might block: yes
+ *
+ *	Notes: Should be called after scsi_add_host()
+ *
+ *	Defined in: drivers/scsi/scsi_scan.c
+ **/
+void scsi_scan_host(struct Scsi_Host *shost)
+
+
 /**
  * scsi_track_queue_full - track successive QUEUE_FULL events on given
  *                      device to determine if and when there is a need