From 1fa81c270da4d8dffa84fcca448654a10ed0a5dc Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Wed, 12 Jan 2011 13:02:28 +0100 Subject: [PATCH] dmaengine i.MX sdma: check sg entries for valid addresses and lengths 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 --- drivers/dma/imx-sdma.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index c50305043f15..8707723e36da 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; -- 2.39.5