On Wed, Mar 19, 2014 at 4:53 AM, Axel Lin <[email protected]> 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 <[email protected]> > --- > 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 -- [email protected] 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 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
