From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Mon, 20 Feb 2017 13:35:47 +0100 Subject: [PATCH] mtd: nand: tango: Enforce DMA direction type In-Reply-To: References: <1486979107-15362-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <20170220133547.06c17a12@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, 20 Feb 2017 13:30:25 +0100 Marc Gonzalez wrote: > On 13/02/2017 10:45, Boris Brezillon wrote: > > > do_dma() use an integer 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 > > Signed-off-by: Boris Brezillon > > --- > > drivers/mtd/nand/tango_nand.c | 9 ++++++--- > > 1 file changed, 6 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/mtd/nand/tango_nand.c b/drivers/mtd/nand/tango_nand.c > > index 4a5e948c62df..9a0e2f85d865 100644 > > --- a/drivers/mtd/nand/tango_nand.c > > +++ b/drivers/mtd/nand/tango_nand.c > > @@ -223,8 +223,8 @@ 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; > > @@ -238,7 +238,10 @@ 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); > > + desc = dmaengine_prep_slave_sg(chan, &sg, 1, > > + dir == DMA_FROM_DEVICE ? > > + DMA_DEV_TO_MEM : DMA_MEM_TO_DEV, > > + DMA_PREP_INTERRUPT); > > if (!desc) > > goto dma_unmap; > > > > > > How about evaluating the ternary conditional into a temp var? Works for me. > > diff --git a/drivers/mtd/nand/tango_nand.c b/drivers/mtd/nand/tango_nand.c > index 4a5e948c62df..c3f145528f1d 100644 > --- a/drivers/mtd/nand/tango_nand.c > +++ b/drivers/mtd/nand/tango_nand.c > @@ -231,6 +231,7 @@ static int do_dma(struct tango_nfc *nfc, int dir, int cmd, const void *buf, > struct dma_async_tx_descriptor *desc; > struct scatterlist sg; > struct completion tx_done; > + int xdir = dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM; > int err = -EIO; > u32 res, val; > > @@ -238,7 +239,7 @@ 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); > + desc = dmaengine_prep_slave_sg(chan, &sg, 1, xdir, DMA_PREP_INTERRUPT); > if (!desc) > goto dma_unmap; >