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path: root/drivers/dma/dmaengine.c
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Diffstat (limited to 'drivers/dma/dmaengine.c')
-rw-r--r--drivers/dma/dmaengine.c21
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index a815d44c70a4..242b8c0a3de8 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -62,6 +62,7 @@
#include <linux/rculist.h>
#include <linux/idr.h>
#include <linux/slab.h>
+#include <linux/of_dma.h>
static DEFINE_MUTEX(dma_list_mutex);
static DEFINE_IDR(dma_idr);
@@ -266,7 +267,10 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
pr_err("%s: timeout!\n", __func__);
return DMA_ERROR;
}
- } while (status == DMA_IN_PROGRESS);
+ if (status != DMA_IN_PROGRESS)
+ break;
+ cpu_relax();
+ } while (1);
return status;
}
@@ -546,6 +550,21 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v
}
EXPORT_SYMBOL_GPL(__dma_request_channel);
+/**
+ * dma_request_slave_channel - try to allocate an exclusive slave channel
+ * @dev: pointer to client device structure
+ * @name: slave channel name
+ */
+struct dma_chan *dma_request_slave_channel(struct device *dev, char *name)
+{
+ /* If device-tree is present get slave info from here */
+ if (dev->of_node)
+ return of_dma_request_slave_channel(dev->of_node, name);
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(dma_request_slave_channel);
+
void dma_release_channel(struct dma_chan *chan)
{
mutex_lock(&dma_list_mutex);