[2/5] dmaengine i.MX sdma: check sg entries for valid addresses and lengths
diff mbox series

Message ID 1296475172-23900-3-git-send-email-s.hauer@pengutronix.de
State New, archived
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Series
  • [1/5] dmaengine i.MX sdma: set maximum segment size for our device
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Commit Message

Sascha Hauer Jan. 31, 2011, 11:59 a.m. UTC
This patch lets sdma_prep_slave_sg fail if the entries of an
sg list do not start on multiples of the word size or if the
lengths are not multiple of the word size.
Also, catch the previously unhandled DMA_SLAVE_BUSWIDTH_8_BYTES
and DMA_SLAVE_BUSWIDTH_UNDEFINED cases.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/dma/imx-sdma.c |   20 +++++++++++++++++---
 1 files changed, 17 insertions(+), 3 deletions(-)

Patch
diff mbox series

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index c503050..8707723 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -925,10 +925,24 @@  static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
 			ret =  -EINVAL;
 			goto err_out;
 		}
-		if (sdmac->word_size == DMA_SLAVE_BUSWIDTH_4_BYTES)
+
+		switch (sdmac->word_size) {
+		case DMA_SLAVE_BUSWIDTH_4_BYTES:
 			bd->mode.command = 0;
-		else
-			bd->mode.command = sdmac->word_size;
+			if (count & 3 || sg->dma_address & 3)
+				return NULL;
+			break;
+		case DMA_SLAVE_BUSWIDTH_2_BYTES:
+			bd->mode.command = 2;
+			if (count & 1 || sg->dma_address & 1)
+				return NULL;
+			break;
+		case DMA_SLAVE_BUSWIDTH_1_BYTE:
+			bd->mode.command = 1;
+			break;
+		default:
+			return NULL;
+		}
 
 		param = BD_DONE | BD_EXTD | BD_CONT;