Re: [PATCH 06/11] spi-dw: Force error on out of range chip select.

[Dirk Brandewie]

On 06/22/2011 08:51 PM, Grant Likely wrote:
> On Wed, Jun 22, 2011 at 8:00 PM,<dirk.brandewie@xxxxxxxxx>  wrote:
> > From: Dirk Brandewie<dirk.brandewie@xxxxxxxxx>
> >
> > BUG_ON() if the selected chip select is out of range.
> >
> > Signed-off-by: Dirk Brandewie<dirk.brandewie@xxxxxxxxx>
> > ---
> >   drivers/spi/spi-dw.h |    3 +--
> >   1 files changed, 1 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
> > index 860bc34..3fa4c13 100644
> > --- a/drivers/spi/spi-dw.h
> > +++ b/drivers/spi/spi-dw.h
> > @@ -178,8 +178,7 @@ static inline void spi_dw_set_clk(struct spi_dw *dws, u16 div)
> >
> >   static inline void spi_dw_chip_sel(struct spi_dw *dws, u16 cs)
> >   {
> > -       if (cs>  dws->num_cs)
> > -               return;
> > +       BUG_ON(cs>= dws->master->num_chipselect);
>
> BUG is rather an over-reaction.  The transfer should be rejected if
> the cs# is invalid, and a warning message is appropriate, but BUG() is
> too extreme.

This is extreme I agree, the current driver will fail silently if an out of 
range chip select is requested.

We can drop this one for now and I will put a proper check in probe/init so we 
won't get here.



> g.

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