[PATCH] mtd: nand: tango: Enforce DMA direction type
Boris Brezillon
boris.brezillon at free-electrons.com
Mon Feb 20 04:35:47 PST 2017
On Mon, 20 Feb 2017 13:30:25 +0100
Marc Gonzalez <marc_gonzalez at sigmadesigns.com> 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 <richard at nod.at>
> > Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> > ---
> > 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;
>
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