1 files changed, 28 insertions, 7 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 97b329e76798..dc003a3a787d 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -169,12 +169,18 @@ static void dma_client_chan_alloc(struct dma_client *client)
         enum dma_state_client ack;
 
         /* Find a channel */
-        list_for_each_entry(device, &dma_device_list, global_node)
+        list_for_each_entry(device, &dma_device_list, global_node) {
+                /* Does the client require a specific DMA controller? */
+                if (client->slave && client->slave->dma_dev
+                                && client->slave->dma_dev != device->dev)
+                        continue;
+
                 list_for_each_entry(chan, &device->channels, device_node) {
                         if (!dma_chan_satisfies_mask(chan, client->cap_mask))
                                 continue;
 
-                        desc = chan->device->device_alloc_chan_resources(chan);
+                        desc = chan->device->device_alloc_chan_resources(
+                                        chan, client);
                         if (desc >= 0) {
                                 ack = client->event_callback(client,
                                                 chan,
@@ -183,12 +189,14 @@ 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;
                         }
                 }
+        }
 }
 
 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
@@ -272,8 +280,10 @@ 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);
@@ -285,6 +295,10 @@ static void dma_clients_notify_removed(struct dma_chan *chan)
  */
 void dma_async_client_register(struct dma_client *client)
 {
+        /* validate client data */
+        BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) &&
+                !client->slave);
+
         mutex_lock(&dma_list_mutex);
         list_add_tail(&client->global_node, &dma_client_list);
         mutex_unlock(&dma_list_mutex);
@@ -313,8 +327,10 @@ 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);
@@ -359,6 +375,10 @@ int dma_async_device_register(struct dma_device *device)
                 !device->device_prep_dma_memset);
         BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
                 !device->device_prep_dma_interrupt);
+        BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
+                !device->device_prep_slave_sg);
+        BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
+                !device->device_terminate_all);
 
         BUG_ON(!device->device_alloc_chan_resources);
         BUG_ON(!device->device_free_chan_resources);
@@ -378,7 +398,7 @@ int dma_async_device_register(struct dma_device *device)
 
                 chan->chan_id = chancnt++;
                 chan->dev.class = &dma_devclass;
-                chan->dev.parent = NULL;
+                chan->dev.parent = device->dev;
                 snprintf(chan->dev.bus_id, BUS_ID_SIZE, "dma%dchan%d",
                          device->dev_id, chan->chan_id);
 
@@ -394,6 +414,7 @@ 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);
         }