Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753299AbcDCKRV (ORCPT ); Sun, 3 Apr 2016 06:17:21 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:49016 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752419AbcDCKRU (ORCPT ); Sun, 3 Apr 2016 06:17:20 -0400 Subject: Re: [PATCH v2 1/1] iio: gyro: bmg160: fix endianness when reading axes To: Irina Tirdea , linux-iio@vger.kernel.org References: <1459255050-2142-1-git-send-email-irina.tirdea@intel.com> Cc: linux-kernel@vger.kernel.org, Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald From: Jonathan Cameron Message-ID: <5700EDAE.2060605@kernel.org> Date: Sun, 3 Apr 2016 11:17:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 In-Reply-To: <1459255050-2142-1-git-send-email-irina.tirdea@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2377 Lines: 68 On 29/03/16 13:37, Irina Tirdea wrote: > For big endian platforms, reading the axes will return > invalid values. > > The device stores each axis value in a 16 bit little > endian register. The driver uses regmap_read_bulk to get > the axis value, resulting in a 16 bit little endian value. > This needs to be converted to cpu endianness to work > on big endian platforms. > > Fix endianness for big endian platforms by converting > the values for the axes read from little endian to > cpu. > > This is also partially fixed in commit 82d8e5da1a33 ("iio: > accel: bmg160: optimize transfers in trigger handler"). > > Signed-off-by: Irina Tirdea Applied to the fixes-togreg-post-rc1 branch and marked for stable. > --- > > Changes from v1: > - pass sizeof(raw_val) to regmap_bulk_read instead of > hardcoded value > > drivers/iio/gyro/bmg160_core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/gyro/bmg160_core.c b/drivers/iio/gyro/bmg160_core.c > index bbce3b0..8d3f0b3 100644 > --- a/drivers/iio/gyro/bmg160_core.c > +++ b/drivers/iio/gyro/bmg160_core.c > @@ -452,7 +452,7 @@ static int bmg160_get_temp(struct bmg160_data *data, int *val) > static int bmg160_get_axis(struct bmg160_data *data, int axis, int *val) > { > int ret; > - unsigned int raw_val; > + __le16 raw_val; > > mutex_lock(&data->mutex); > ret = bmg160_set_power_state(data, true); > @@ -462,7 +462,7 @@ static int bmg160_get_axis(struct bmg160_data *data, int axis, int *val) > } > > ret = regmap_bulk_read(data->regmap, BMG160_AXIS_TO_REG(axis), &raw_val, > - 2); > + sizeof(raw_val)); > if (ret < 0) { > dev_err(data->dev, "Error reading axis %d\n", axis); > bmg160_set_power_state(data, false); > @@ -470,7 +470,7 @@ static int bmg160_get_axis(struct bmg160_data *data, int axis, int *val) > return ret; > } > > - *val = sign_extend32(raw_val, 15); > + *val = sign_extend32(le16_to_cpu(raw_val), 15); > ret = bmg160_set_power_state(data, false); > mutex_unlock(&data->mutex); > if (ret < 0) > @@ -733,6 +733,7 @@ static const struct iio_event_spec bmg160_event = { > .sign = 's', \ > .realbits = 16, \ > .storagebits = 16, \ > + .endianness = IIO_LE, \ > }, \ > .event_spec = &bmg160_event, \ > .num_event_specs = 1 \ >