[SCSI] modify change_queue_depth to take in reason why it is being called

This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
	Also converted pmcraid_change_queue_depth and then verified
all modules compile  using "make allmodconfig" for any new build
warnings on X86_64.

	Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 7 insertions, 2 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b4ee28dec521..5d52c2fcd076 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1208,6 +1208,7 @@ void ata_scsi_slave_destroy(struct scsi_device *sdev)
  *      ata_scsi_change_queue_depth - SCSI callback for queue depth config
  *      @sdev: SCSI device to configure queue depth for
  *      @queue_depth: new queue depth
+ *      @reason: calling context
  *
  *      This is libata standard hostt->change_queue_depth callback.
  *      SCSI will call into this callback when user tries to set queue
@@ -1219,12 +1220,16 @@ void ata_scsi_slave_destroy(struct scsi_device *sdev)
  *      RETURNS:
  *      Newly configured queue depth.
  */
-int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
+int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth,
+                                int reason)
 {
         struct ata_port *ap = ata_shost_to_port(sdev->host);
         struct ata_device *dev;
         unsigned long flags;
 
+        if (reason != SCSI_QDEPTH_DEFAULT)
+                return -EOPNOTSUPP;
+
         if (queue_depth < 1 || queue_depth == sdev->queue_depth)
                 return sdev->queue_depth;
 
diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index 1eb4e020eb5c..0c82d335c55d 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -1975,7 +1975,7 @@ static int nv_swncq_slave_config(struct scsi_device *sdev)
         ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
 
         if (strncmp(model_num, "Maxtor", 6) == 0) {
-                ata_scsi_change_queue_depth(sdev, 1);
+                ata_scsi_change_queue_depth(sdev, 1, SCSI_QDEPTH_DEFAULT);
                 ata_dev_printk(dev, KERN_NOTICE,
                         "Disabling SWNCQ mode (depth %x)\n", sdev->queue_depth);
         }