From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:46887 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752754AbcKSNIB (ORCPT ); Sat, 19 Nov 2016 08:08:01 -0500 Subject: Re: [PATCH v2] iio: common: st_sensors: fix channel data parsing To: Lorenzo Bianconi References: <1479330928-7208-1-git-send-email-lorenzo.bianconi@st.com> Cc: linux-iio@vger.kernel.org, lorenzo.bianconi@st.com, Gregor Boirie , Linus Walleij From: Jonathan Cameron Message-ID: Date: Sat, 19 Nov 2016 13:07:58 +0000 MIME-Version: 1.0 In-Reply-To: <1479330928-7208-1-git-send-email-lorenzo.bianconi@st.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 16/11/16 21:15, Lorenzo Bianconi wrote: > Using realbits as i2c/spi read len, when that value is not byte aligned > (e.g 12 bits), lead to skip msb part of out data registers. > Fix this taking into account scan_type.shift in addition to > scan_type.realbits as read length: > > read_len = DIV_ROUND_UP(realbits + shift, 8) > > This fix has been tested on 8, 12, 16, 24 bit sensors > > Fixes: e7385de5291e ("iio:st_sensors: align on storagebits boundaries") > Signed-off-by: Lorenzo Bianconi Do highlight (typically below the --) what changes have occurred. I'm guessing this was mostly about testing on the 24 bit sensor and the additions in the core file. Applied to the fixes-togreg and marked for stable. I will probably sit on this one for a few days before sending upstream if anyone has any final comments on it. Thanks, Jonathan > --- > drivers/iio/common/st_sensors/st_sensors_buffer.c | 4 +++- > drivers/iio/common/st_sensors/st_sensors_core.c | 4 +++- > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c > index fe7775b..df40452 100644 > --- a/drivers/iio/common/st_sensors/st_sensors_buffer.c > +++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c > @@ -30,7 +30,9 @@ static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf) > > for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) { > const struct iio_chan_spec *channel = &indio_dev->channels[i]; > - unsigned int bytes_to_read = channel->scan_type.realbits >> 3; > + unsigned int bytes_to_read = > + DIV_ROUND_UP(channel->scan_type.realbits + > + channel->scan_type.shift, 8); > unsigned int storage_bytes = > channel->scan_type.storagebits >> 3; > > diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c > index 975a1f1..d5cf7f3 100644 > --- a/drivers/iio/common/st_sensors/st_sensors_core.c > +++ b/drivers/iio/common/st_sensors/st_sensors_core.c > @@ -483,8 +483,10 @@ static int st_sensors_read_axis_data(struct iio_dev *indio_dev, > int err; > u8 *outdata; > struct st_sensor_data *sdata = iio_priv(indio_dev); > - unsigned int byte_for_channel = ch->scan_type.realbits >> 3; > + unsigned int byte_for_channel; > > + byte_for_channel = DIV_ROUND_UP(ch->scan_type.realbits + > + ch->scan_type.shift, 8); > outdata = kmalloc(byte_for_channel, GFP_KERNEL); > if (!outdata) > return -ENOMEM; >