From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:43897 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752078AbbHWPsm (ORCPT ); Sun, 23 Aug 2015 11:48:42 -0400 Subject: Re: [PATCH v3 1/2] iio: humidity: si7020: replaced bitmask on humidity values with range check To: Nicola Corna , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald References: <1440333248-3450-1-git-send-email-nicola@corna.info> Cc: linux-iio@vger.kernel.org From: Jonathan Cameron Message-ID: <55D9EB58.50304@kernel.org> Date: Sun, 23 Aug 2015 16:48:40 +0100 MIME-Version: 1.0 In-Reply-To: <1440333248-3450-1-git-send-email-nicola@corna.info> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 23/08/15 13:34, Nicola Corna wrote: > The maximum possible value for the relative humidity is 55575 (100%RH). > This value, if shifted right by 2 bits, uses 14 bits and masking it with > a 12 bit mask removes 2 meaningful bits. > The masking has been replaced with a range check that sets the minimum > value at 786 (0%RH) and the maximum at 13893 (99.998%RH). > > Signed-off-by: Nicola Corna > Reviewed-by: Hartmut Knaack Applied. I have taken the view that previously the driver was 'limited' by this rather than a nasty bug. Hence I've queued it up for the next merge window. Applied to the togreg branch of iio.git Thanks, Jonathan > --- > drivers/iio/humidity/si7020.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c > index fa3b809..06e6659 100644 > --- a/drivers/iio/humidity/si7020.c > +++ b/drivers/iio/humidity/si7020.c > @@ -57,8 +57,12 @@ static int si7020_read_raw(struct iio_dev *indio_dev, > if (ret < 0) > return ret; > *val = ret >> 2; > + /* > + * Humidity values can slightly exceed the 0-100%RH > + * range and should be corrected by software > + */ > if (chan->type == IIO_HUMIDITYRELATIVE) > - *val &= GENMASK(11, 0); > + clamp_val(*val, 786, 13893); > return IIO_VAL_INT; > case IIO_CHAN_INFO_SCALE: > if (chan->type == IIO_TEMP) >