Re: [PATCH 11/11] spi-dw: remove noop else clause

[Dirk Brandewie]

On 06/22/2011 07:47 PM, Feng Tang wrote:
> On Thu, 23 Jun 2011 10:00:13 +0800
> "dirk.brandewie@xxxxxxxxx"<dirk.brandewie@xxxxxxxxx>  wrote:
>
> > From: Dirk Brandewie<dirk.brandewie@xxxxxxxxx>
> >
> > The value of spi->bits_per_word is checked on function entry to be 8
> > or 16.  The else clause has no meaning since it can never be reached.
> >
> > Signed-off-by: Dirk Brandewie<dirk.brandewie@xxxxxxxxx>
> > ---
> >   drivers/spi/spi-dw.c |    9 +++------
> >   1 files changed, 3 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
> > index 7b3f607..5ddd45f 100644
> > --- a/drivers/spi/spi-dw.c
> > +++ b/drivers/spi/spi-dw.c
> > @@ -667,17 +667,14 @@ static int spi_dw_setup(struct spi_device *spi)
> >   		chip->enable_dma = chip_info->enable_dma;
> >   	}
> >
> > -	if (spi->bits_per_word<= 8) {
> > +	if (spi->bits_per_word == 8) {
> >   		chip->n_bytes = 1;
> >   		chip->dma_width = 1;
> > -	} else if (spi->bits_per_word<= 16) {
> > +	} else if (spi->bits_per_word == 16) {
> >   		chip->n_bytes = 2;
> >   		chip->dma_width = 2;
> > -	} else {
> > -		/* Never take>16b case for DW SPIC */
> > -		dev_err(&spi->dev, "invalid wordsize\n");
> > -		return -EINVAL;
> >   	}
>
> These "else" case is used to ban the slave spi devices which
> try to use 32 bits per word mode. This is like to tell those
> spi devices with 32 bpw capability "we don't support 32b, pls
> change"

The function has the prerequisite code:
	if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
		return -EINVAL;

at the begining of the function so we will never be able to reach the else 
clause that is being removed.

> > +
> >   	chip->bits_per_word = spi->bits_per_word;
> >
> >   	chip->speed_hz = spi->max_speed_hz;

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