esp_scsi: make number of tags configurable

Add a field 'num_tags' to the esp structure to allow drivers
to overwrite the number of avialable tags if required.
Default is ESP_DEFAULT_TAGS.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

2 files changed, 7 insertions, 8 deletions

diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index 7e7687f73deb..57ccb147b22b 100644
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -2317,6 +2317,10 @@ int scsi_esp_register(struct esp *esp, struct device *dev)
         static int instance;
         int err;
 
+        if (!esp->num_tags)
+                esp->num_tags = ESP_DEFAULT_TAGS;
+        else if (esp->num_tags >= ESP_MAX_TAG)
+                esp->num_tags = ESP_MAX_TAG - 1;
         esp->host->transportt = esp_transport_template;
         esp->host->max_lun = ESP_MAX_LUN;
         esp->host->cmd_per_lun = 2;
@@ -2403,12 +2407,8 @@ static int esp_slave_configure(struct scsi_device *dev)
         struct esp *esp = shost_priv(dev->host);
         struct esp_target_data *tp = &esp->target[dev->id];
 
-        if (dev->tagged_supported) {
-                /* XXX make this configurable somehow XXX */
-                int goal_tags = min(ESP_DEFAULT_TAGS, ESP_MAX_TAG);
-
-                scsi_change_queue_depth(dev, goal_tags);
-        }
+        if (dev->tagged_supported)
+                scsi_change_queue_depth(dev, esp->num_tags);
 
         tp->flags |= ESP_TGT_DISCONNECT;
 
diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h
index b5862e463455..975d2934d42a 100644
--- a/drivers/scsi/esp_scsi.h
+++ b/drivers/scsi/esp_scsi.h
@@ -283,7 +283,6 @@ struct esp_cmd_entry {
         struct completion       *eh_done;
 };
 
-/* XXX make this configurable somehow XXX */
 #define ESP_DEFAULT_TAGS        16
 
 #define ESP_MAX_TARGET          16
@@ -445,7 +444,7 @@ struct esp {
         u8                      prev_soff;
         u8                      prev_stp;
         u8                      prev_cfg3;
-        u8                      __pad;
+        u8                      num_tags;
 
         struct list_head        esp_cmd_pool;