dmaengine: track the number of clients using a channel

[firefly-linux-kernel-4.4.55.git] / drivers / dma / dmaengine.c

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 99c22b42bada79dbbd834bf09156e00f3fef81ff..10de69eb1a3e1e01479b35a2f66fc6cdcc21559b 100644 (file)
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -183,9 +183,10 @@ static void dma_client_chan_alloc(struct dma_client *client)
                                /* we are done once this client rejects
                                 * an available resource
                                 */
-                               if (ack == DMA_ACK)
+                               if (ack == DMA_ACK) {
                                        dma_chan_get(chan);
-                               else if (ack == DMA_NAK)
+                                       chan->client_count++;
+                               } else if (ack == DMA_NAK)
                                        return;
                        }
                }
@@ -272,8 +273,10 @@ static void dma_clients_notify_removed(struct dma_chan *chan)
                /* client was holding resources for this channel so
                 * free it
                 */
-               if (ack == DMA_ACK)
+               if (ack == DMA_ACK) {
                        dma_chan_put(chan);
+                       chan->client_count--;
+               }
        }
 
        mutex_unlock(&dma_list_mutex);
@@ -313,8 +316,10 @@ void dma_async_client_unregister(struct dma_client *client)
                        ack = client->event_callback(client, chan,
                                DMA_RESOURCE_REMOVED);
 
-                       if (ack == DMA_ACK)
+                       if (ack == DMA_ACK) {
                                dma_chan_put(chan);
+                               chan->client_count--;
+                       }
                }
 
        list_del(&client->global_node);
@@ -394,6 +399,7 @@ int dma_async_device_register(struct dma_device *device)
                kref_get(&device->refcount);
                kref_get(&device->refcount);
                kref_init(&chan->refcount);
+               chan->client_count = 0;
                chan->slow_ref = 0;
                INIT_RCU_HEAD(&chan->rcu);
        }