static void mport_cdev_release_dma()

in devices/rio_mport_cdev.c [1943:1999]

• 48 lines of code
• 6 McCabe index (conditional complexity)

static void mport_cdev_release_dma(struct file *filp)
{
	struct mport_cdev_priv *priv = filp->private_data;
	struct mport_dev *md;
	struct mport_dma_req *req, *req_next;
	unsigned long tmo = msecs_to_jiffies(dma_timeout);
	long wret;
	LIST_HEAD(list);

	rmcd_debug(EXIT, "from filp=%p %s(%d)",
		   filp, current->comm, task_pid_nr(current));

	if (!priv->dmach) {
		rmcd_debug(EXIT, "No DMA channel for filp=%p", filp);
		return;
	}

	md = priv->md;

	spin_lock(&priv->req_lock);
	if (!list_empty(&priv->async_list)) {
		rmcd_debug(EXIT, "async list not empty filp=%p %s(%d)",
			   filp, current->comm, task_pid_nr(current));
		list_splice_init(&priv->async_list, &list);
	}
	spin_unlock(&priv->req_lock);

	if (!list_empty(&list)) {
		rmcd_debug(EXIT, "temp list not empty");
		list_for_each_entry_safe(req, req_next, &list, node) {
			rmcd_debug(EXIT, "free req->filp=%p cookie=%d compl=%s",
				   req->filp, req->cookie,
				   completion_done(&req->req_comp)?"yes":"no");
			list_del(&req->node);
			kref_put(&req->refcount, dma_req_free);
		}
	}

	put_dma_channel(priv);
	wret = wait_for_completion_interruptible_timeout(&priv->comp, tmo);

	if (wret <= 0) {
		rmcd_error("%s(%d) failed waiting for DMA release err=%ld",
			current->comm, task_pid_nr(current), wret);
	}

	if (priv->dmach != priv->md->dma_chan) {
		rmcd_debug(EXIT, "Release DMA channel for filp=%p %s(%d)",
			   filp, current->comm, task_pid_nr(current));
		rio_release_dma(priv->dmach);
	} else {
		rmcd_debug(EXIT, "Adjust default DMA channel refcount");
		kref_put(&md->dma_ref, mport_release_def_dma);
	}

	priv->dmach = NULL;
}