[SCSI] ibmvscsi: Changeable queue depth

Adds support for a changeable queue depth to ibmvscsi.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 19 insertions, 0 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index b10eefe735c5..b580af95956b 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -1375,6 +1375,23 @@ static int ibmvscsi_slave_configure(struct scsi_device *sdev)
         return 0;
 }
 
+/**
+ * ibmvscsi_change_queue_depth - Change the device's queue depth
+ * @sdev:       scsi device struct
+ * @qdepth:     depth to set
+ *
+ * Return value:
+ *      actual depth set
+ **/
+static int ibmvscsi_change_queue_depth(struct scsi_device *sdev, int qdepth)
+{
+        if (qdepth > IBMVSCSI_MAX_CMDS_PER_LUN)
+                qdepth = IBMVSCSI_MAX_CMDS_PER_LUN;
+
+        scsi_adjust_queue_depth(sdev, 0, qdepth);
+        return sdev->queue_depth;
+}
+
 /* ------------------------------------------------------------
  * sysfs attributes
  */
@@ -1521,6 +1538,7 @@ static struct scsi_host_template driver_template = {
         .eh_abort_handler = ibmvscsi_eh_abort_handler,
         .eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,
         .slave_configure = ibmvscsi_slave_configure,
+        .change_queue_depth = ibmvscsi_change_queue_depth,
         .cmd_per_lun = 16,
         .can_queue = IBMVSCSI_MAX_REQUESTS_DEFAULT,
         .this_id = -1,
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.h b/drivers/scsi/ibmvscsi/ibmvscsi.h
index 77cc1d40f5bb..727ca7c95926 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.h
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.h
@@ -45,6 +45,7 @@ struct Scsi_Host;
 #define MAX_INDIRECT_BUFS 10
 
 #define IBMVSCSI_MAX_REQUESTS_DEFAULT 100
+#define IBMVSCSI_MAX_CMDS_PER_LUN 64
 
 /* ------------------------------------------------------------
  * Data Structures