Re: [PATCH 1/7] spi: core: Validate Tx/Rx buffers for non-zero length transfer

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

On Wed, Mar 19, 2014 at 4:53 AM, Axel Lin <axel.lin@xxxxxxxxxx> wrote:
> Reject transfer if both tx_buf and rx_buf are NULL for non-zero length transfer.
> Add the checking in spi core so we can remove the same checking in various
> drivers.

Just wondering: are there any SPI slave drivers that implement dummy cycles
this way?

> Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
> ---
>  drivers/spi/spi.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 26b331d..0a29d2a 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -1876,6 +1876,10 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
>                 if (xfer->len % w_size)
>                         return -EINVAL;
>
> +               /* non-zero length transfer must has tx_buf or rx_buf */

have

> +               if (xfer->len && !xfer->tx_buf && !xfer->rx_buf)
> +                       return -EINVAL;
> +

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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