[PATCH 1/2] dmaengine: Add helper macro dmaengine_prep_submit()

[Frank Li <Frank.Li@nxp.com>]

Previously, DMA users had to call dmaengine_prep_*() followed by
dmaengine_submit(). Many DMA consumers missed call dmaengine_desc_free()
when dmaengine_submit() returned an error.

Introduce dmaengine_prep_submit() to combine preparation and submission
into a single step and ensure the descriptor is freed on submission
failure.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 include/linux/dmaengine.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 99efe2b9b4ea9844ca6161208362ef18ef111d96..78246fd8a8294b6764d2717d73b9c49842f64696 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -1249,6 +1249,22 @@ static inline dma_cookie_t dmaengine_submit(struct dma_async_tx_descriptor *desc
 	return desc->tx_submit(desc);
 }
 
+#define dmaengine_prep_submit(chan, cb, cb_param, func, ...)	\
+({	struct dma_async_tx_descriptor *tx =			\
+		dmaengine_prep_##func(chan, __VA_ARGS__);	\
+	dma_cookie_t cookie = -ENOMEM;				\
+								\
+	if (tx) {						\
+		tx->callback = cb;				\
+		tx->callback_param = cb_param;			\
+		cookie = dmaengine_submit(tx);			\
+								\
+		if (dma_submit_error(cookie))			\
+			dmaengine_desc_free(tx);		\
+	}							\
+	cookie;							\
+})
+
 static inline bool dmaengine_check_align(enum dmaengine_alignment align,
 					 size_t off1, size_t off2, size_t len)
 {

-- 
2.34.1