MFD: AB8500 mask off irrelevant bits from the SPI message
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From: Samuel Ortiz on 17 Jun 2010 15:20 Hi Linus, On Thu, Jun 17, 2010 at 06:46:42PM +0200, Linus Walleij wrote: > 2010/5/28 Linus Walleij <linus.walleij(a)stericsson.com>: > > > The registers on the AB8500 are only 8 bits wide, so the content > > of the remaining bits is undefined. Let's mask off the undefined > > stuff when returning a register in an SPI read. > > Are you picking this one up Samuel? Yes, sorry for the delay, I've been quite busy with other projects but will go through my MFD backlog in a day or 2. Cheers, Samuel. > Yours, > Linus Walleij -- Intel Open Source Technology Centre http://oss.intel.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Samuel Ortiz on 18 Jun 2010 17:20
Hi Linus, On Fri, May 28, 2010 at 02:59:44AM +0200, Linus Walleij wrote: > The registers on the AB8500 are only 8 bits wide, so the content > of the remaining bits is undefined. Let's mask off the undefined > stuff when returning a register in an SPI read. Patch applied, sorry for the delay. Cheers, Samuel. > Acked-by: Rabin Vincent <rabin.vincent(a)stericsson.com> > Signed-off-by: Linus Walleij <linus.walleij(a)stericsson.com> > --- > drivers/mfd/ab8500-spi.c | 7 ++++++- > 1 files changed, 6 insertions(+), 1 deletions(-) > > diff --git a/drivers/mfd/ab8500-spi.c b/drivers/mfd/ab8500-spi.c > index b81d4f7..e1c8b62 100644 > --- a/drivers/mfd/ab8500-spi.c > +++ b/drivers/mfd/ab8500-spi.c > @@ -68,7 +68,12 @@ static int ab8500_spi_read(struct ab8500 *ab8500, u16 addr) > > ret = spi_sync(spi, &msg); > if (!ret) > - ret = ab8500->rx_buf[0]; > + /* > + * Only the 8 lowermost bytes are > + * defined with value, the rest may > + * vary depending on chip/board noise. > + */ > + ret = ab8500->rx_buf[0] & 0xFFU; > > return ret; > } > -- > 1.6.3.3 > -- Intel Open Source Technology Centre http://oss.intel.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |