Merge branch 'topic/async' into for-linus

3 files changed, 25 insertions, 1 deletions

diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
index 5b2395e7e04d..c3468094393e 100644
--- a/drivers/dma/dma-axi-dmac.c
+++ b/drivers/dma/dma-axi-dmac.c
@@ -307,6 +307,13 @@ static int axi_dmac_terminate_all(struct dma_chan *c)
         return 0;
 }
 
+static void axi_dmac_synchronize(struct dma_chan *c)
+{
+        struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
+
+        vchan_synchronize(&chan->vchan);
+}
+
 static void axi_dmac_issue_pending(struct dma_chan *c)
 {
         struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
@@ -613,6 +620,7 @@ static int axi_dmac_probe(struct platform_device *pdev)
         dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic;
         dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved;
         dma_dev->device_terminate_all = axi_dmac_terminate_all;
+        dma_dev->device_synchronize = axi_dmac_synchronize;
         dma_dev->dev = &pdev->dev;
         dma_dev->chancnt = 1;
         dma_dev->src_addr_widths = BIT(dmac->chan.src_width);
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 21c8c0bce3af..c50a247be2e0 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -266,8 +266,11 @@ static void dma_chan_put(struct dma_chan *chan)
         module_put(dma_chan_to_owner(chan));
 
         /* This channel is not in use anymore, free it */
-        if (!chan->client_count && chan->device->device_free_chan_resources)
+        if (!chan->client_count && chan->device->device_free_chan_resources) {
+                /* Make sure all operations have completed */
+                dmaengine_synchronize(chan);
                 chan->device->device_free_chan_resources(chan);
+        }
 
         /* If the channel is used via a DMA request router, free the mapping */
         if (chan->router && chan->router->route_free) {
diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h
index bff8c39dd716..d9731ca5e262 100644
--- a/drivers/dma/virt-dma.h
+++ b/drivers/dma/virt-dma.h
@@ -163,4 +163,17 @@ static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
         vchan_dma_desc_free_list(vc, &head);
 }
 
+/**
+ * vchan_synchronize() - synchronize callback execution to the current context
+ * @vc: virtual channel to synchronize
+ *
+ * Makes sure that all scheduled or active callbacks have finished running. For
+ * proper operation the caller has to ensure that no new callbacks are scheduled
+ * after the invocation of this function started.
+ */
+static inline void vchan_synchronize(struct virt_dma_chan *vc)
+{
+        tasklet_kill(&vc->task);
+}
+
 #endif