rapidio: fix return value description for dma_prep functions
Update return value description for rio_dma_prep_... functions to
include error-valued pointer that can be returned by HW mport device
drivers. Return values from these functions must be checked using
IS_ERR_OR_NULL macro.
This patch is applicable to kernel versions starting from v4.6-rc1.
Link: http://lkml.kernel.org/r/1469125134-16523-4-git-send-email-alexandre.bounine@idt.com
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Barry Wood <barry.wood@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index 0dcaa66..8408029 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -1848,7 +1848,9 @@
* Initializes RapidIO capable DMA channel for the specified data transfer.
* Uses DMA channel private extension to pass information related to remote
* target RIO device.
- * Returns pointer to DMA transaction descriptor or NULL if failed.
+ *
+ * Returns: pointer to DMA transaction descriptor if successful,
+ * error-valued pointer or NULL if failed.
*/
struct dma_async_tx_descriptor *rio_dma_prep_xfer(struct dma_chan *dchan,
u16 destid, struct rio_dma_data *data,
@@ -1883,7 +1885,9 @@
* Initializes RapidIO capable DMA channel for the specified data transfer.
* Uses DMA channel private extension to pass information related to remote
* target RIO device.
- * Returns pointer to DMA transaction descriptor or NULL if failed.
+ *
+ * Returns: pointer to DMA transaction descriptor if successful,
+ * error-valued pointer or NULL if failed.
*/
struct dma_async_tx_descriptor *rio_dma_prep_slave_sg(struct rio_dev *rdev,
struct dma_chan *dchan, struct rio_dma_data *data,