1 files changed, 33 insertions, 6 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index ea806bdc12ef..92caad629d99 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -540,6 +540,8 @@ EXPORT_SYMBOL_GPL(dma_get_slave_channel);
  * @mask: capabilities that the channel must satisfy
  * @fn: optional callback to disposition available channels
  * @fn_param: opaque parameter to pass to dma_filter_fn
+ *
+ * Returns pointer to appropriate DMA channel on success or NULL.
  */
 struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
                                        dma_filter_fn fn, void *fn_param)
@@ -591,18 +593,43 @@ 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
+ *
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
  */
-struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name)
+struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
+                                                  const char *name)
 {
+        struct dma_chan *chan;
+
         /* If device-tree is present get slave info from here */
         if (dev->of_node)
                 return of_dma_request_slave_channel(dev->of_node, name);
 
         /* If device was enumerated by ACPI get slave info from here */
-        if (ACPI_HANDLE(dev))
-                return acpi_dma_request_slave_chan_by_name(dev, name);
+        if (ACPI_HANDLE(dev)) {
+                chan = acpi_dma_request_slave_chan_by_name(dev, name);
+                if (chan)
+                        return chan;
+        }
 
-        return NULL;
+        return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
+
+/**
+ * dma_request_slave_channel - try to allocate an exclusive slave channel
+ * @dev:        pointer to client device structure
+ * @name:       slave channel name
+ *
+ * Returns pointer to appropriate DMA channel on success or NULL.
+ */
+struct dma_chan *dma_request_slave_channel(struct device *dev,
+                                           const char *name)
+{
+        struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
+        if (IS_ERR(ch))
+                return NULL;
+        return ch;
 }
 EXPORT_SYMBOL_GPL(dma_request_slave_channel);
 
@@ -912,7 +939,7 @@ struct dmaengine_unmap_pool {
 #define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
 static struct dmaengine_unmap_pool unmap_pool[] = {
         __UNMAP_POOL(2),
-        #if IS_ENABLED(CONFIG_ASYNC_TX_DMA)
+        #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
         __UNMAP_POOL(16),
         __UNMAP_POOL(128),
         __UNMAP_POOL(256),
@@ -1054,7 +1081,7 @@ dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg,
         dma_cookie_t cookie;
         unsigned long flags;
 
-        unmap = dmaengine_get_unmap_data(dev->dev, 2, GFP_NOIO);
+        unmap = dmaengine_get_unmap_data(dev->dev, 2, GFP_NOWAIT);
         if (!unmap)
                 return -ENOMEM;