*/
int scsi_change_queue_depth(struct scsi_device *sdev, int depth)
{
- unsigned long flags;
-
- if (depth <= 0)
- goto out;
-
- spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
-
- /*
- * Check to see if the queue is managed by the block layer.
- * If it is, and we fail to adjust the depth, exit.
- *
- * Do not resize the tag map if it is a host wide share bqt,
- * because the size should be the hosts's can_queue. If there
- * is more IO than the LLD's can_queue (so there are not enuogh
- * tags) request_fn's host queue ready check will handle it.
- */
- if (!shost_use_blk_mq(sdev->host) && !sdev->host->bqt) {
- if (blk_queue_tagged(sdev->request_queue) &&
- blk_queue_resize_tags(sdev->request_queue, depth) != 0)
- goto out_unlock;
+ if (depth > 0) {
+ sdev->queue_depth = depth;
+ wmb();
}
- sdev->queue_depth = depth;
-out_unlock:
- spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
-out:
return sdev->queue_depth;
}
EXPORT_SYMBOL(scsi_change_queue_depth);