dmaengine: andes: atcdmac300: add the content of the follow-up changes for PR torvalds#156 (torvalds#176)

The content of PR torvalds#156 was already merged in a previous commit (de3c459c26).
The follow-up changes [1] are added here.

[1] https://gitea.andestech.com/RD-SW/linux/compare/01d1ae22c9ab20726915cab6c82d386d4d27062a..c94d7e80569465af5feb2cb652b7e8dad2a7679c

Signed-off-by: charles <[email protected]>

Reviewed-on: https://gitea.andestech.com/RD-SW/linux/pulls/176
Reviewed-by: CL Chin-Long Wang <[email protected]>
Reviewed-by: randolph <[email protected]>
Co-authored-by: charles <[email protected]>
Co-committed-by: charles <[email protected]>

Author: CharlesWu465

drivers/dma/atcdmac300.c

@@ -27,12 +27,13 @@
 	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\
 	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
 
-#define INIT_DESC(desc) do {					\
-				desc->at = NULL;		\
-				desc->cyclic = false;		\
-				desc->num_sg = 0;		\
-				INIT_LIST_HEAD(&desc->tx_list);	\
-			} while (0)
+#define INIT_DESC(desc)				\
+	do {					\
+		desc->at = NULL;		\
+		desc->cyclic = false;		\
+		desc->num_sg = 0;		\
+		INIT_LIST_HEAD(&desc->tx_list);	\
+	} while (0)
 
 static unsigned int init_nr_desc_per_channel = 64;
 module_param(init_nr_desc_per_channel, uint, 0644);
@@ -144,8 +145,9 @@ static struct v5_desc *v5_desc_get(struct v5_dma_chan *v5chan)
 /**
  * v5_desc_put_nolock - move a descriptor to the free list.
  *
- * This function does not use a lock to protect the free linked list,
- * so please remember to add a proper lock when calling the function.
+ * This function does not use a lock to protect any linked lists in
+ * 'struct v5_dma_chan', so please remember to add a proper lock when
+ * calling the function.
  *
  * @v5chan: channel we work on
  * @desc: descriptor, at the head of a chain, to move to free list
@@ -164,13 +166,11 @@ static void v5_desc_put_nolock(struct v5_dma_chan *v5chan, struct v5_desc *desc)
 		INIT_DESC(desc);
 		list_add_tail(&desc->desc_node, &v5chan->free_list);
 
-		index = 1;
-		while (index < num_sg) {
+		for (index = 1; index < num_sg; index++) {
 			desc = list_entry(next_node, struct v5_desc, desc_node);
 			next_node = desc->desc_node.next;
 			INIT_DESC(desc);
 			list_add_tail(&desc->desc_node, &v5chan->free_list);
-			index++;
 		}
 	}
 }

drivers/dma/atcdmac300.h

@@ -237,7 +237,7 @@ enum v5_status {
  * .device_config
  * @lock: serializes enqueue/dequeue operations to descriptors lists
  * @chan_used: This variable shows that the DMA channel is in use and
-               prevents new DMA operations on it.
+ *	       prevents new DMA operations on it.
  * @active_list: list of descriptors dmaengine is being running on
  * @queue: list of descriptors ready to be submitted to engine
  * @free_list: list of descriptors usable by the channel