Thread (6 messages) flat view 6 messages, 3 authors, 2017-03-16
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[PATCH v2] mtd: nand: tango: Enforce DMA direction type

From: Boris Brezillon <hidden>
Date: 2017-03-16 09:27:19

On Mon, 20 Feb 2017 14:10:07 +0100
Marc Gonzalez [off-list ref] wrote:
From: Boris Brezillon <redacted>

do_dma() uses an int to pass the DMA data direction information and
pass the same value to dmaengine_prep_slave_sg().

Currently, DMA_{FROM,TO}_DEVICE match DMA_{DEV_TO_MEM,MEM_TO_DEV}
definitions so it works fine, but assuming this will always be the case
is not safe.

Enforce enum dma_data_direction type in the function prototype and make
the enum dma_data_direction -> enum dma_transfer_direction conversion
explicit.

Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Boris Brezillon <redacted>
Acked-by: Marc Gonzalez <redacted>
Applied.
quoted hunk ↗ jump to hunk
---
 drivers/mtd/nand/tango_nand.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/mtd/nand/tango_nand.c b/drivers/mtd/nand/tango_nand.c
index 4a5e948c62df..05b6e1065203 100644
--- a/drivers/mtd/nand/tango_nand.c
+++ b/drivers/mtd/nand/tango_nand.c
@@ -223,12 +223,13 @@ static void tango_dma_callback(void *arg)
 	complete(arg);
 }
 
-static int do_dma(struct tango_nfc *nfc, int dir, int cmd, const void *buf,
-		  int len, int page)
+static int do_dma(struct tango_nfc *nfc, enum dma_data_direction dir, int cmd,
+		  const void *buf, int len, int page)
 {
 	void __iomem *addr = nfc->reg_base + NFC_STATUS;
 	struct dma_chan *chan = nfc->chan;
 	struct dma_async_tx_descriptor *desc;
+	enum dma_transfer_direction tdir;
 	struct scatterlist sg;
 	struct completion tx_done;
 	int err = -EIO;
@@ -238,7 +239,8 @@ static int do_dma(struct tango_nfc *nfc, int dir, int cmd, const void *buf,
 	if (dma_map_sg(chan->device->dev, &sg, 1, dir) != 1)
 		return -EIO;
 
-	desc = dmaengine_prep_slave_sg(chan, &sg, 1, dir, DMA_PREP_INTERRUPT);
+	tdir = dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
+	desc = dmaengine_prep_slave_sg(chan, &sg, 1, tdir, DMA_PREP_INTERRUPT);
 	if (!desc)
 		goto dma_unmap;
 
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