diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 99c22b42bada79dbbd834bf09156e00f3fef81ff..10de69eb1a3e1e01479b35a2f66fc6cdcc21559b 100644 --- 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); } diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index d08a5c5eb928f3f2d8ef8639a518b0ac37fb6c89..6432b83432201ab5e431c32e2b163b5d1c6388c7 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -139,6 +139,7 @@ struct dma_chan_percpu { * @rcu: the DMA channel's RCU head * @device_node: used to add this to the device chan list * @local: per-cpu pointer to a struct dma_chan_percpu + * @client-count: how many clients are using this channel */ struct dma_chan { struct dma_device *device; @@ -154,6 +155,7 @@ struct dma_chan { struct list_head device_node; struct dma_chan_percpu *local; + int client_count; }; #define to_dma_chan(p) container_of(p, struct dma_chan, dev)